Search

Ultracentrifugation is an attractive method for separating full and empty capsids, exploiting their density difference. Changes of the serotype/capsid, density of loading material, or the genetic information contained in the adeno-associated viruses (AAVs) require the adaptation of the harvesting parameters and the density gradient loaded onto the centrifuge. To streamline these adaptations, a mathematical model could support the design and testing of operating conditions. Here, hybrid models, which combine empirical functions with artificial neural networks, are proposed to describe the separation of full and empty capsids as a function of material and operational parameters, i.e., the harvest model. In addition, critical quality attributes are estimated by a quality model which is operating on top of the harvest model. The performance of these models was evaluated using test data and two additional blind runs. Also, a "what-if" analysis was conducted to investigate whether the models' predictions align with expectations. It is concluded that the models are sufficiently accurate to support the design of operating conditions, though the accuracy and applicability of the models can further be increased by training them on more specific data with higher variability. [ABSTRACT FROM AUTHOR]

The addition of d = 5 operators to the Seesaw model leads to the Dimension-5 Seesaw Portal. Here, two new operators provide interactions for the heavy sterile neutrinos. In particular, the Higgs boson can have a large branching ratio into two heavy neutrinos, meaning that these states can be searched for at the LHC. Moreover, the heavy neutrinos can now decay dominantly into light neutrinos and photons. If the heavy neutrinos are long-lived, then searches for delayed, non-pointing photons can constrain the model. In this work, we carry out a detailed recast of an ATLAS search for such displaced photons, triggered by a charged lepton produced in association to the Higgs, placing bounds on the branching ratio for Higgs decay into two heavy neutrinos as low as 2%. [ABSTRACT FROM AUTHOR]

We consider a coarse-grained polymer model in order to investigate the origin of a recently discovered negative energy-related contribution to the elastic modulus G(T) of rubber-like gels. From this model, we are able to compute an exact expression for the free energy of the system, which allows us to evaluate a stress–strain relationship that displays a non-trivial dependence on the temperature T. We validate our approach through comparisons between the theoretical results and the experimental data obtained for tetra-PEG hydrogels, which indicate that, although simple, the present model works well to describe the experiments. Importantly, our approach unveiled aspects of the experimental analysis which turned out to be different from the conventional entropic and energetic analysis broadly used in the literature. Also, in contrast to the linear dependence predicted by the traditional, i.e., purely entropic, models, our results suggest that the general expression of the elastic modulus should be of the form G (T) ∝ k B T w (T) , with w(T) being a temperature-dependent correction factor that could be related to the interaction between the chains in the network and the solvent. Accordingly, the correction factor allows the expression found for the elastic modulus to describe both rubber and rubber-like gels. [ABSTRACT FROM AUTHOR]

We propose the first Search for Dark Sector at the Brazilian Synchrotron Light Laboratory, site of Sirius, a fourth-generation storage ring. We show that UVX, Sirius predecessor, can be a promising dark sector detector, SeDS, with unprecedented sensitivity. The search is based on a 1 - 3 GeV positron beam impinging on a thick target leading the e + e - → γ A ′ reaction, followed by a missing mass spectrum event reconstruction. We show that SeDS has the potential to probe dark photons with masses up to 55 MeV and kinetic coupling down to ϵ 2 ∼ 10 - 12 . Therefore, such experiment would constitute the best dark photon probe worldwide in the 10 - 55 MeV mass range, being able to probe an unexplored region of parameter space. [ABSTRACT FROM AUTHOR]

The Dimension-5 Seesaw Portal is a Type-I Seesaw model extended by d = 5 operators involving the sterile neutrino states, leading to new interactions between all neutrinos and the Standard Model neutral bosons. In this work we focus primarily on the implications of these new operators at the GeV-scale. In particular, we recalculate the heavy neutrino full decay width, up to three-body decays. We also review bounds on the dipole operator, and revisit LEP constraints on its coefficient. Finally, we turn to heavy neutrino pair production from Higgs decays, where the former are long-lived and disintegrate into a photon and a light neutrino. We probe this process by recasting two ATLAS searches for non-pointing photons, showing the expected event distribution in terms of arrival time tγ and pointing variable |∆zγ|. [ABSTRACT FROM AUTHOR]

Genetic factors explain a major proportion of human height variation, but differences in mean stature have also been found between socio-economic categories suggesting a possible effect of environment. By utilizing a classical twin design which allows decomposing the variation of height into genetic and environmental components, we tested the hypothesis that environmental variation in height is greater in offspring of lower educated parents. Twin data from 29 cohorts including 65,978 complete twin pairs with information on height at ages 1 to 69 years and on parental education were pooled allowing the analyses at different ages and in three geographic-cultural regions (Europe, North America and Australia, and East Asia). Parental education mostly showed a positive association with offspring height, with significant associations in mid-childhood and from adolescence onwards. In variance decomposition modeling, the genetic and environmental variance components of height did not show a consistent relation to parental education. A random-effects meta-regression analysis of the aggregate-level data showed a trend towards greater shared environmental variation of height in low parental education families. In conclusion, in our very large dataset from twin cohorts around the globe, these results provide only weak evidence for the study hypothesis. [ABSTRACT FROM AUTHOR]

Many aspects of the supposed hyperthermal Toarcian Oceanic Anoxic Event (T-OAE, Early Jurassic, c. 182 Ma) are well understood but a lack of robust palaeotemperature data severely limits reconstruction of the processes that drove the T-OAE and associated environmental and biotic changes. New oxygen isotope data from calcite shells of the benthic fauna suggest that bottom water temperatures in the western Tethys were elevated by c. 3.5 °C through the entire T-OAE. Modelling supports the idea that widespread marine anoxia was induced by a greenhouse-driven weathering pulse, and is compatible with the OAE duration being extended by limitation of the global silicate weathering flux. In the western Tethys Ocean, the later part of the T-OAE is characterized by abundant occurrences of the brachiopod Soaresirhynchia, which exhibits characteristics of slow-growing, deep sea brachiopods. The unlikely success of Soaresirhynchia in a hyperthermal event is attributed here to low metabolic rate, which put it at an advantage over other species from shallow epicontinental environments with higher metabolic demand. [ABSTRACT FROM AUTHOR]

The Maytenus genus is a member of the Celastraceae family. Numerous medicinal uses were assigned to species of this genus, with the use of roots, bark, and leaves for the treatment of gastric ulcers, as anti-inflammatory, analgesic, antiallergic, antitumor, among others. Several studies have demonstrated that natural products derived from plants have an important role in the prevention and treatment of obesity. Accordingly, we evaluated the effect of Maytenus imbricata extracts in the treatment of obesity induced by diet rich in refined carbohydrate (HC). BALB/c mice were fed chow or HC diet for 8 weeks. At the beginning of the 9th week, the HC group was subdivided into three groups: (i) group of animals that continued to consume only HC diet; (ii) the group of animals fed HC diet supplemented with ethyl acetate extract of M. imbricata roots (HC + EAE); (iii) the group of animals fed HC diet supplemented with extract in hexane/ethyl ether (HC + HEE). The period of extracts supplementation was 4 weeks. It was observed that EAE and EHE when added to the HC diet modulated the metabolic and inflammatory changes, such as: reduced the adipocytes area, improved glucose intolerance, reduced the levels of triglycerides and resistin in serum, and the number of total leukocytes in blood. In the epididymal adipose tissue, the extracts reduced proinflammatory mediators' concentration. According to the results, it was concluded that the species Maytenus imbricata has the potential to be used for the treatment of obesity. [ABSTRACT FROM AUTHOR]

It remains unclear so far whether the role of cognitive reserve for cognitive functioning in old age may differ between individuals with low, compared to those with high functional fitness status. Therefore, the present study set out to investigate the relation of education and cognitive leisure activity as key markers of cognitive reserve to mini-mental state in old age (as an indicator of the extent of cognitive impairment) and its interplay with functional fitness status in a large sample of older adults. We assessed MMSE in 701 older adults (M = 70.4 years, SD = 6.9, range: 60-91). We measured functional fitness status using the Senior Fitness Test battery and interviewed individuals on their education and cognitive leisure activity. Results showed that better functional fitness status, longer education, and greater engagement in cognitive leisure activity were significantly related to higher MMSE scores. Moderation analyses showed that the relations of education and cognitive leisure activity to MMSE scores were significantly larger in individuals with low, compared to those with high functional fitness status. In conclusion, cognitive functioning in old age may more strongly depend on cognitive reserve accumulated during the life course in older adults with low, compared to those with high functional fitness status. These findings may be explained by cross-domain compensation effects in vulnerable individuals and may (at least partly) account for the large variability in cognitive reserve-cognition relations debated in the literature. [ABSTRACT FROM AUTHOR]

Mayaro fever, caused by Mayaro virus (MAYV) is a sub-lethal disease with symptoms that are easily confused with those of dengue fever, except for polyarthralgia, which may culminate in physical incapacitation. Recently, outbreaks of MAYV have been documented in metropolitan areas, and to date, there is no therapy or vaccine available. Moreover, there is no information regarding the three-dimensional structure of the viral proteins of MAYV, which is important in the search for antivirals. In this work, we constructed a three-dimensional model of protein C of MAYV by homology modelling, and this was employed in a manner similar to that of receptors in virtual screening studies to evaluate 590 molecules as prospective antiviral agents. In vitro bioassays were utilized to confirm the potential antiviral activity of the flavonoid epicatechin isolated from Salacia crassifolia (Celastraceae). The virtual screening showed that six flavonoids were promising ligands for protein C. The bioassays showed potent antiviral action of epicatechin, which protected the cells from almost all of the effects of viral infection. An effective concentration (EC50) of 0.247 μmol/mL was observed with a selectivity index (SI) of 7. The cytotoxicity assay showed that epicatechin has low toxicity, with a 50% cytotoxic concentration (CC50) greater than 1.723 µmol/mL. Epicatechin was found to be twice as potent as the reference antiviral ribavirin. Furthermore, a replication kinetics assay showed a strong inhibitory effect of epicatechin on MAYV growth, with a reduction of at least four logs in virus production. Our results indicate that epicatechin is a promising candidate for further testing as an antiviral agent against Mayaro virus and other alphaviruses. [ABSTRACT FROM AUTHOR]

Several works have shown that triterpenes induce peripheral antinociception by activation of cannabinoid receptors and endocannabinoids; besides, several research groups have reported activation of cannabinoid receptors in peripheral antinociception. The aim of this study was to assess the involvement of the cannabinoid system in the antinociceptive effect induced by tingenone against hyperalgesia evoked by prostaglandin E (PGE) at peripheral level. The paw pressure test was used and the hyperalgesia was induced by intraplantar injection of PGE (2 μg/paw). All drugs were injected subcutaneously in the hind paws of male Swiss mice. Tingenone (200 µg/paw) administered into the right hind paw induced a local antinociceptive effect, that was antagonized by AM630, a selective antagonist to CB cannabinoid receptor. AM251, a selective antagonist to CB cannabinoid receptor, did not alter the peripheral antinociceptive effect of tingenone. MAFP, a fatty acid amide hydrolase (FAAH) inhibitor; VDM11, an anandamide reuptake inhibitor; and JZL184, monoacylglycerol lipase (MAGL) inhibitor did not potentiate the peripheral antinociceptive effect of the lower dose of tingenone (50 µg/paw). The results suggest that tingenone induced a peripheral antinociceptive effect via cannabinoid receptor activation. Therefore, this study suggests a pharmacological potential for a new analgesic drug. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed (1) to examine the role of potential correlates of HRQoL in a large representative sample of older adults, and (2) to investigate whether the relationships between HRQoL and potential factors differ as a function of HRQoL component (physical vs. mental) and/or age cohort (young-old vs. old-old).Methods: This cross-sectional study included 802 older adults aged 60-79 years old. HRQoL was assessed using the SF-36 questionnaire. Functional fitness was assessed using the Senior Fitness Test. Physical activity was measured via the Baecke questionnaire. Demographic information, mental and health features were obtained through questionnaires.Results: A multiple regression analysis showed that BMI (β = -0.15, p = 0.001), body strength (β = 0.21, p < 0.001), aerobic endurance (β = 0.29, p < 0.001), physical activity (β = 0.11, p = 0.007), depressive symptoms (β = -0.19, p < 0.001), falls (β = -0.19, p < 0.001), and living alone (β = -0.16, p < 0.001) were all significantly related to HRQoL-SF-36 total score. The positive relation with aerobic endurance was significantly higher for the physical component of HRQoL, while the negative relation with living alone was significantly higher for the mental component. The positive relation of HRQoL with physical activity was significantly higher in old-old compared to young-old adults.Conclusion: This data suggest that body composition, functional fitness, psycho-social factors, and falls are important correlates of HRQoL in old age. There are HRQoL-component and age-cohort differences regarding these correlates, underlying the need for specific strategies at the community level to promote HRQoL in older adults. [ABSTRACT FROM AUTHOR]

1:CAS:528:DyaK3cXjtFKksg%3D%3D. 10.1093/nar/17.19.7843 3 Hunter G, Plummer S, Denman S (2013) Development of a real-time PCR assay for the identification of Brenneria goodwinii, associated with Acute Oak Decline (AOD) of Quercus spp. in the United Kingdom. In March 2018, an acute oak decline (AOD) was observed on a I Quercus suber i forest in Alcácer, Alentejo. Reisolation of colonies with similar morphology and PCR identification confirmed the pathogenicity of the inoculated strains and positive controls. [Extracted from the article]

Groundwater pollution is a major environmental concern at global scale. It usually restricts the use of water resources for domestic, agricultural or industrial purposes, with significant impact on human well-being. Aquifer remediation may be very difficult or even impossible due to technical and/or economic constraints. To help prevent groundwater pollution, several cartographic methods have already been developed. Geographical information systems (GIS) provide useful tools for understanding the spatial distribution of groundwater vulnerability to pollution. This paper presents a new tool to produce groundwater vulnerability to pollution maps under a GIS open source environment. This application was developed within the QGIS software. The tool determines the spatial distribution of the DRASTIC index and incorporates all the procedures required under a single plugin. One of the main advantages of this application is the easiness to use and the possibility of viewing different results modifying indexes, weight values and table descriptions or importing the input data attribute file description. The user can also generate the maps according to his perception regarding each aquifer system. This application is free and presents a valuable contribution to assess and map groundwater vulnerability to pollution through a GIS open source. [ABSTRACT FROM AUTHOR]

Small-scale siliceous sponge-microbialite buildups are recorded in the Middle-Upper Toarcian hemipelagic succession (marl-limestone alternations) of the Lusitanian Basin. A detailed study of these buildups from different outcrops recorded in the eastern area of the basin (Zambujal, Ordem, and Roça Cú) made it possible to characterize the typology of these buildups, identify the different components and facies, and discuss the controlling factors involved. The studied buildups developed in three growth stages: (I) a colonization stage of the muddy bottom by epibenthic macroinvertebrates, resulting in bioclastic patches providing a hard substrate, functioning as benthic islands; (II) a growth stage dominated by dish-shaped siliceous sponges encrusted by thin microbial crusts; (III) a growth stage dominated by thick microbial growth (thrombolites and minority leiolites) on siliceous sponges. This sequence is repeated in more complex buildups with cycles of growth, interruption, and resumption. The competition for available hard substrates among sessile benthic organisms, including microbial communities, reinforced the buildup growth with respect to the surrounding unfavorable soft substrate and controlled the high variability of the accompanying fauna. The installation of these buildups in the outer homoclinal ramp was favored by a low sedimentation rate, water depth, and type and availability of nutrients. Changes in the composition of sponge assemblages indicate decreasing dissolved organic carbon and colloidal substances along with increasing particulate organic matter, probably related with a shallowing-upward trend and a regressive phase. [ABSTRACT FROM AUTHOR]

Several species and varieties of the family Crassulaceae have been introduced and cultivated for ornamental as well as medicinal purposes in Brazil, more prominently Cotyledon orbiculata (pig's ear). This work reports the identification and characterization of viruses associated with foliar mosaic and distortion of C. orbiculata from the succulent plant collection of the garden of the University of São Paulo, Brazil. In situ analyses revealed enveloped bacilliform particles in the perinuclear space of infected C. orbiculata cells, and cytoplasmic cylindrical inclusions, typical of the family Potyviridae. Viruses were mechanically transmitted and separated by differential indicator hosts and aphid transmission (Myzus persicae). Chenopodium amaranticolor and Datura stramonium served as differential hosts for the potyvirus and the bacilliform virus, respectively. Positive serological reactions were obtained when leaf extracts from naturally infected C. orbiculata and experimental hosts were exposed to an antiserum to Sonchus yellow net virus (genus Nucleorhabdovirus). Identification of the potyvirus by RT-PCR, cloning into pGEM-T vector and sequencing generated a 1,752 nt fragment corresponding to part of the nuclear inclusion protein b (NIb), the complete coat protein (CP) and the untranslated region (UTR). Amino acid identities below 80% and phylogenetic analyses indicated that the potyvirus of C. orbiculata may be a new species belonging to the Potato virus Y subgroup, for which the name Cotyledon virus Y (CotVY) is suggested. [ABSTRACT FROM AUTHOR]

In Brazil, the state of São Paulo contains both preserved areas (Juréia-Itatins Ecological Station) and extremely impacted ones (Cubatão Municipality). This study evaluated the concentrations of five metals (Cu, Cd, Cr, Pb, and Hg) in two mangroves with different levels of anthropogenic impact and the apparent genotoxicity to Ucides cordatus. Water and sediment samples were obtained, and metal concentrations were determined with an atomic absorption spectrophotometer. The genotoxic impact was quantified based on the number of micronucleated cells per 1,000 analyzed (MN‰), using hemolymph slides stained with Giemsa. Metal concentrations in water were below the detection limit, except for lead, although no significant difference was observed between the areas ( P > 0.05). Sediment from Cubatão had higher concentrations of Cd, Pb, Cr, and Cu than sediment from Juréia-Itatins ( P < 0.05), but no significant differences in metal concentrations were detected among depth strata of the sediment ( P > 0.05). Crabs from Cubatão had a 2.6 times higher mean frequency of micronucleated cells (5.2 ± 1.8 MN‰) than those from Juréia-Itatins (2.0 ± 1.0 MN‰; P < 0.0001). The more-polluted conditions found in the mangrove sediments of Cubatão were reflected in the micronucleus assay, demonstrating their genotoxic effect; however, genetic damage should be attributed to a synergistic effect with other kinds of pollutants previously recorded in different environments of Cubatão. U. cordatus proved to be an excellent bioindicator of mangrove pollution. This study established, for the first time, the normal frequency of MN‰ in a population of this species within an ecological station. [ABSTRACT FROM AUTHOR]

The PROBA2 Science Centre (P2SC) is a small-scale science operations centre supporting the Sun observation instruments onboard PROBA2: the EUV imager Sun Watcher using APS detectors and image Processing (SWAP) and Large-Yield Radiometer (LYRA). PROBA2 is one of ESA's small, low-cost Projects for Onboard Autonomy (PROBA) and part of ESA's In-Orbit Technology Demonstration Programme. The P2SC is hosted at the Royal Observatory of Belgium, co-located with both Principal Investigator teams. The P2SC tasks cover science planning, instrument commanding, instrument monitoring, data processing, support of outreach activities, and distribution of science data products. PROBA missions aim for a high degree of autonomy at mission and system level, including the science operations centre. The autonomy and flexibility of the P2SC is reached by a set of web-based interfaces allowing the operators as well as the instrument teams to monitor quasi-continuously the status of the operations, allowing a quick reaction to solar events. In addition, several new concepts are implemented at instrument, spacecraft, and ground-segment levels allowing a high degree of flexibility in the operations of the instruments. This article explains the key concepts of the P2SC, emphasising the automation and the flexibility achieved in the commanding as well as the data-processing chain. [ABSTRACT FROM AUTHOR]

The structural study of two (CHO) pentacyclic triterpene (PCTT) isomers is presented. These terpenes, known as 30-hydroxy-lup-20(29)-en-3-one ( 1) and (11α)-11-hydroxy-lup-20(29)-en-3-one ( 2), were isolated from Maytenus imbricata Mart. Ex Reissek (Celastraceae). The molecular structure of 1 and 2 differs in the position of the hydroxyl group. Both compounds crystallize in non-centrosymmetric space groups with two molecules in the asymmetric unit. The crystal structure of 1 shows a triclinic P1 space group ( a = 9.5518(1) Å, b = 9.7083(1) Å, c = 14.4696(2) Å, α = 93.832(1)°, β = 102.833(1)°, and γ = 103.307(1)°), while compound 2 crystallizes in a monoclinic P2 one ( a = 13.4439(16) Å, b = 14.4463(14) Å, c = 13.5224(9) Å and β = 99.703(8)°). The two molecules independent by symmetry of 1 differ slightly due to the presence of static disorder in oxygen atoms. In addition, the intermolecular geometries of 1 and 2 were analysed, and in each isomer the crystal packing is stabilized by O-H...O intermolecular hydrogen bonds and van der Waals forces. [ABSTRACT FROM AUTHOR]

We introduce a mapping related to the Nyman–Beurling approach to the Riemann hypothesis. This mapping allows us to clarify the arithmetical nature of inner products for expansions of the “fractional part” functions. We also simplify the deduction of Vasyunin's cotangent formulas. Bibliography: 5 titles. [ABSTRACT FROM AUTHOR]

The effect of changing growth rate and oxygen transfer rate (OTR) on Debaryomyces hansenii physiology was studied using xylose-limited and oxygen-limited chemostat cultures, respectively, and complemented with enzymatic assays. Under xylose-limited chemostat (oxygen-excess), neither ethanol nor xylitol was produced over the entire range of dilution rate (D). The maximal volumetric biomass productivity was 2.5 g l–1 h–1 at D =0.25 h–1 and cell yield was constant at all values of D. The respiratory rates and xylose consumption rate increased linearly with growth rate but, above 0.17 h–1, oxygen consumption rate had a steeper increase compared to carbon dioxide production rate. Enzymatic analysis of xylose metabolism suggests that internal fluxes are redirected as a function of growth rate. For values of D up to 0.17 h–1, the xylose reductase (XR) titre is lower than the xylitol dehydrogenase (XDH) titre, whereas above 0.17 h–1 XR activity is about twice that of XDH and the NADPH-producing enzymes sharply increase their titres indicating an internal metabolic flux shift to meet higher NADPH metabolic requirements. Moreover, the enzymes around the pyruvate node also exhibited different patterns if D was above or below 0.17 h–1. Under oxygen-limited chemostat (xylose-excess) the metabolism changed drastically and, due to oxidative phosphorylation limitation, cell yield decreased to 0.16 g g–1 for an OTR of 1.4 mmol l–1 h–1 and xylitol became the major extracellular product along with minor amounts of glycerol. The enzymatic analysis revealed that isocitrate dehydrogenase is not regulated by oxygen, whereas XR, XDH and the NADPH-producing enzymes changed their levels according to oxygen availability. [ABSTRACT FROM AUTHOR]

Copyright of Archives of Orthopaedic & Traumatic Surgery / Archiv für Orthopädie, Mechanotherapie und Unfallchirurgie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We describe the ground segment, pre-launch operations concepts, and data products supporting the SOHO mission. Our goal is threefold: first, we provide a historical view of the design and development of the systems described here, as a background perspective to those who will use the system and those who may build such systems for future missions. Second, because we hope that many researchers from the solar and space physics communities will visit these facilities during the mission, we provide an overview for the benefit of the end-user. We anticipate that visitors to GSFC may plan observations for one or more of SOHO's complement of instruments, and such researchers may use the facilities to analyze data gathered by the SOHO instruments. Third, we present the working plan for investigators with groundbased or other spacebased instruments to collaborate with SOHO. [ABSTRACT FROM AUTHOR]

In this theoretical communication we look towards understand the underlying phenomenology concerning the Elko spinors within VSR theory. The program to be accomplished here start when we define the eigenspinors of the charge conjugation operator as eigenstates of the helicity operator in the Cartesian coordinates system. This prescription is very useful in the sense of phenomenological point of view, so, we propose a set of Elko spinors ready to be computationally implemented. Regardless of, in order to show the application of given approach we impose to these spinors to be restrict to an axis, coincidentally the axis of locality (Ahluwalia-Khalilova and Grumiller in JCAP, 07:12 2005; Ahluwalia-Khalilova and Cheng-Yang Lee in Phys Rev D 83:065017, 2011) , and then, using the proposed prescription, we search for physical amounts and physical processes by analysing the Yukawa and the self-interaction in such framework. [ABSTRACT FROM AUTHOR]

Soil erosion is a serious environmental problem. An estimation of the expected soil loss by water-caused erosion can be calculated considering the Revised Universal Soil Loss Equation (RUSLE). Geographical Information Systems (GIS) provide different tools to create categorical maps of soil erosion risk which help to study the risk assessment of soil loss. The objective of this study was to develop a GIS open source application (in QGIS), using the RUSLE methodology for estimating erosion rate at the watershed scale (desktop application) and provide the same application via web access (web application). The applications developed allow one to generate all the maps necessary to evaluate the soil erosion risk. Several libraries and algorithms from SEXTANTE were used to develop these applications. These applications were tested in Montalegre municipality (Portugal). The maps involved in RUSLE method—soil erosivity factor, soil erodibility factor, topographic factor, cover management factor, and support practices—were created. The estimated mean value of the soil loss obtained was 220 ton km−2 year−1 ranged from 0.27 to 1283 ton km−2 year−1. The results indicated that most of the study area (80 %) is characterized by very low soil erosion level (<321 ton km−2 year−1) and in 4 % of the studied area the soil erosion was higher than 962 ton km−2 year−1. It was also concluded that areas with high slope values and bare soil are related with high level of erosion and the higher the P and C values, the higher the soil erosion percentage. The RUSLE web and the desktop application are freely available. [ABSTRACT FROM AUTHOR]