Dynamic regimes of hydrodynamically coupled self-propelling particles

We analyze the collective dynamics of self-propelling particles (spps) which move at small Reynolds numbers including the hydrodynamic coupling to the suspending solvent through numerical simulations. The velocity distribution functions show marked deviations from Gaussian behavior at short times, and the mean-square displacement at long times shows a transition from diffusive to ballistic motion for appropriate driving mechanism at low concentrations. We discuss the structures the spps form at long times and how they correlate to their dynamic behavior.Comment: 7 pages, 4 figure

Decision making under uncertainty in environmental projects using mathematical simulation modeling

The final publication is available at Springer via http://dx.doi.org/10.1007/s12665-016-6135-yIn decision-making processes, reliability and risk aversion play a decisive role. The aim of this study is to perform an uncertainty assessment of the effects of future scenarios of sustainable groundwater pumping strategies on the quantitative and chemical status of an aquifer. The good status of the aquifer is defined according to the terms established by the EU Water Framework Directive (WFD). A decision support systems (DSS) is presented, which makes use of a stochastic inverse model (GC method) and geostatistical approaches to calibrate equally likely realizations of hydraulic conductivity (K) fields for a particular case study. These K fields are conditional to available field data, including hard and soft information. Then, different future scenarios of groundwater pumping strategies are generated, based on historical information and WFD standards, and simulated for each one of the equally likely K fields. The future scenarios lead to different environmental impacts and levels of socioeconomic development of the region and, hence, to a different degree of acceptance among stakeholders. We have identified the different stakeholders implied in the decision-making process, the objectives pursued and the alternative actions that should be considered by stakeholders in a public participation project (PPP). The MonteCarlo simulation provides a highly effective way for uncertainty assessment and allows presenting the results in a simple and understandable way even for non-experts stakeholders. The methodology has been successfully applied to a real case study and lays the foundations to performa PPP and stakeholders' involvement in a decisionmaking process as required by the WFD. The results of the methodology can help the decision-making process to come up with the best policies and regulations for a groundwater system under uncertainty in groundwater parameters and management strategies and involving stakeholders with conflicting interests.Llopis Albert, C.; Palacios Marqués, D.; Merigó -Lindahl, JM. (2016). Decision making under uncertainty in environmental projects using mathematical simulation modeling. Environmental Earth Sciences. 75(19):1-11. doi:10.1007/s12665-016-6135-yS1117519Arhonditsis GB, Perhar G, Zhang W, Massos E, Shi M, Das A (2008) Addressing equifinality and uncertainty in eutrophication models. Water Resour Res 44:W01420. doi: 10.1029/2007WR005862Capilla JE, Llopis-Albert C (2009) Gradual conditioning of non-gaussian transmissivity fields to flow and mass transport data. J Hydrol 371:66–74. doi: 10.1016/j.jhydrol.2009.03.015CHJ (Júcar Water Agency) (2016) Júcar river basin authority. http://www.chj.es/CHS (Segura Water Agency) (2016) Segura river basin authority. http://www.chsegura.es/Custodio E (2002) Aquifer overexploitation: what does it mean? Hydrogeol J 10:254–277EC (2000). Directive 2000/60/EC of the European Parliament and of the Council of October 23 2000, establishing a framework for community action in the field of water policy. Official Journal of the European Communities L327/1eL327/72. 22.12.2000EC (2006) Directive 2006/118/EC of the European Parliament and of the Council of 12 December 2006 on the protection of groundwater against pollution and deteriorationGómez-Hernández JJ, Srivastava RM (1990) ISIM3D: an ANSI-C three dimensional multiple indicator conditional simulation program. Comput Geosci 16(4):395–440Harbaugh AW, Banta ER, Hill MC and McDonald MG (2000) MODFLOW- 2000, The US geological survey modular groundwater model-user guide to modularization concepts and the groundwater flow process. US Geol. Surv. Open-File Rep 00–92, 12Hu LY (2000) Gradual deformation and iterative calibration of Gaussian related stochastic models. Math Geol 32(1):87–108Jagelke J, Barthel R (2005) Conceptualization and implementation of a regional groundwater model for the Neckar catchment in the framework of an integrated regional model. Adv Geosci 5:105–111Llopis-Albert C (2008) Stochastic inverse modeling conditional to flow, mass transport and secondary information. Universitat Politècnica de València, València. ISBN 978-84-691-9796-7Llopis-Albert C, Capilla JE (2009a) Gradual conditioning of non-gaussian transmissivity fields to flow and mass transport data. Demonstration on a synthetic aquifer. J Hydrol 371:53–55. doi: 10.1016/j.jhydrol.2009.03.014Llopis-Albert C, Capilla JE (2009b) Gradual conditioning of non-gaussian transmissivity fields to flow and mass transport data. Application to the macrodispersion experiment (MADE-2) site, on Columbus air force base in Mississippi (USA). J Hydrol 371:75–84. doi: 10.1016/j.jhydrol.2009.03.016Llopis-Albert C, Capilla JE (2010a) Stochastic simulation of non-gaussian 3D conductivity fields in a fractured medium with multiple statistical populations: a case study. J Hydrol Eng 15(7):554–566. doi: 10.1061/(ASCE)HE.1943-5584.0000214Llopis-Albert C, Capilla JE (2010b) Stochastic inverse modeling of hydraulic conductivity fields taking into account independent stochastic structures: a 3D case study. J Hydrol 391:277–288. doi: 10.1016/j.jhydrol.2010.07.028Llopis-Albert C, Pulido-Velazquez D (2014) Discussion about the validity of sharp-interface models to deal with seawater intrusion in coastal aquifers. Hydrol Process 28(10):3642–3654Llopis-Albert C, Pulido-Velazquez D (2015) Using MODFLOW code to approach transient hydraulic head with a sharp-interface solution. Hydrol Process 29(8):2052–2064. doi: 10.1002/hyp.10354Llopis-Albert C, Palacios-Marqués D, Merigó JM (2014) A coupled stochastic inverse-management framework for dealing with nonpoint agriculture pollution under groundwater parameter uncertainty. J Hydrol 511:10–16. doi: 10.1016/j.jhydrol.2014.01.021Llopis-Albert C, Merigó JM, Palacios-Marqués D (2015) Structure adaptation in stochastic inverse methods for integrating information. Water Resour Manage 29(1):95–107. doi: 10.1007/s11269-014-0829-2Llopis-Albert C, Merigó JM, Xu Y (2016) A coupled stochastic inverse/sharp interface seawater intrusion approach for coastal aquifers under groundwater parameter uncertainty. J Hydrol 540:774–783. doi: 10.1016/j.jhydrol.2016.06.065McDonald MG and Harbaugh AW (1988) A modular three-dimensional finite-difference groundwater flow model. US geological survey technical manual of water resources investigation, Book 6, US geological survey, Reston, Virginia, 586Molina JL, Pulido-Velazquez M, Llopis-Albert C, Peña-Haro S (2013) Stochastic hydro-economic model for groundwater quality management using Bayesian networks. Water Sci Technol 67(3):579–586. doi: 10.2166/wst.2012.598Peña-Haro S, Llopis-Albert C, Pulido-Velazquez M (2010) Fertilizer standards for controlling groundwater nitrate pollution from agriculture: El Salobral-Los Llanos case study, Spain. J Hydrol 392:174–187. doi: 10.1016/j.jhydrol.2010.08.006Peña-Haro S, Pulido-Velazquez M, Llopis-Albert C (2011) Stochastic hydro-economic modeling for optimal management of agricultural groundwater nitrate pollution under hydraulic conductivity uncertainty. Environ Model Softw 26(8):999–1008. doi: 10.1016/j.envsoft.2011.02.010Pulido-Velazquez D, Llopis-Albert C, Peña-Haro S, Pulido-Velazquez M (2011) Efficient conceptual model for simulating the effect of aquifer heterogeneity on natural groundwater discharge to rivers. Adv Water Resour 34(11):1377–1389. doi: 10.1016/j.advwatres.2011.07.010Reichert P, Borsuk M, Hostmann M, Schweizer S, Spörri C, Tockner K, Truffer B (2005) Concepts of decision support for river rehabilitation. Environ Model Softw 22:188–201Wright SAL, Fritsch O (2011) Operationalising active involvement in the EU water framework directive: why, when and how? Ecol Econ 70(12):2268–2274Zhou H, Gómez-Hernández JJ, Li L (2014) Inverse methods in hydrogeology: evolution and recent trends. Adv Water Resour 63:22–37. doi: 10.1016/j.advwatres.2013.10.01

Comprehensive Seepage Assessment: Beaver Dam, Arkansas

A general philosophy of the role of engineering geology and engineering geophysics in seepage assessment is presented. Practical application of this philosophy is illustrated by a case history. A large dike continues to have anomalous seepage in spite of pre-construction and postconstruction grouting. The dike is founded over a graben of cavernous limestone with about a 200-ft. vertical offset along the bounding fault zones, which are horizontally separated by about 1000 ft. Objectives of the seepage assessment program were to define the geological and hydrological conditions beneath the dike in sufficient detail to allow rational remedial planning. Integration of results of a geophysical investigation with the overall assessment program is emphasized: preliminary interpretation of the geophysical results is used to site new piezometers; detailed analysis of the geophysical results is used to site exploratory borings; feedback from exploratory borings and new piezometers is used to refine geophysical interpretation

Toxicological assessment of mesoporous silica particles in the nematode Caenorhabditis elegans

[EN] Here we report the toxicological evaluation of mesoporous silica particles (MSPs) in the nematode C. elegans. Specifically, we have investigated the effect of bare micro- (M0) and nano-sized (N0) MSPs, and their corresponding functionalized particles with a starch derivative (Glu-N) (M1 and N1, respectively) on C. elegans ageing parameters. The toxicity of MSPs, their impact on C. elegans lifespan, movement capacity, progeny and ability to survive upon exposure to acute oxidative stress were assessed. This study demonstrated that both size particles assayed (M0 and N0), labeled with rhodamine and monitored through fluorescence microscopy, are ingested by the nematode. Moreover, toxicity assays indicated that bare nano-sized particles (N0) have a negative impact on the C. elegans lifespan, reducing mobility and progeny production. By contrast, micro-sized particles (M0) proved innocuous for the nematodes. Furthermore, functionalization of nanoparticles with starch derivative reduced their toxicity in C. elegans. Thus, oral intake of N1 comparatively increased the mean lifespan and activity rates as well as resistance to oxidative stress. The overall findings presented here demonstrate the influence of MSP size and surface on their potential toxicity in vivo and indicate the silica-based mesoporous particles to be a potential support for encapsulation in oral delivery applications. Furthermore, the good correlation obtained between healthy aging variables and viability (mean lifespan) validates the use of C. elegans as a multicellular organism for nanotoxicology studies of MSPs.The authors wish to express their gratitude to the Spanish Government (MINECO Projects AGL2012-39597-C02-01, AGL2012-39597-C02-02, AGL2015-70235-C2-1, MAT2012-38429-C04-01 and MAT2015-64139-C4-1), the Generalitat Valenciana (Project PROMETEOII/2014/047) and Colombian Administrative Department of Science, Technology and Research which supported Ms. Acosta Scholarship. We would also like to thank the Institut de Ciencia dels Materials (ICMUV), the Microscopy Service of the Universitat Politecnica de Valencia and the microscopy service of IATA for technical support. We thank Roquette for the Glucidex samples.Acosta-Romero, C.; Barat Baviera, JM.; Martínez-Máñez, R.; Sancenón Galarza, F.; Llopis Llopis, S.; Gonzalez, N.; Genovés, S.... (2018). Toxicological assessment of mesoporous silica particles in the nematode Caenorhabditis elegans. Environmental Research. 166:61-70. https://doi.org/10.1016/j.envres.2018.05.018S617016

When are active Brownian particles and run-and-tumble particles equivalent? Consequences for motility-induced phase separation

Active Brownian particles (ABPs, such as self-phoretic colloids) swim at fixed speed $v$ along a body-axis ${\bf u}$ that rotates by slow angular diffusion. Run-and-tumble particles (RTPs, such as motile bacteria) swim with constant \u until a random tumble event suddenly decorrelates the orientation. We show that when the motility parameters depend on density $\rho$ but not on ${\bf u}$, the coarse-grained fluctuating hydrodynamics of interacting ABPs and RTPs can be mapped onto each other and are thus strictly equivalent. In both cases, a steeply enough decreasing $v(\rho)$ causes phase separation in dimensions $d=2,3$, even when no attractive forces act between the particles. This points to a generic role for motility-induced phase separation in active matter. However, we show that the ABP/RTP equivalence does not automatically extend to the more general case of \u-dependent motilities

Sermón de la seráfica Madre Santa Theresa de Jesús : que en la solemne fiesta, que anualmente la consagran ... sus hijos los PP. Carmelitas Descalzos, en el Convento de San Joseph de la ciudad de Barcelona

Copia digital : Junta de Castilla y León. Consejería de Cultura y Turismo, 2014Sign.: A8, []8

Inhibición de la formación de ácidos grasos volátiles durante la fermentación ruminal ¨in vitro¨ por colistina, kanamicina y penicilina

Se ha estudiado el efecto de tres antibióticos: Kanamicina, Penicilina y Colistina a las dosis de 0,125 a 2,50 mg/ml; 50 a 1.000 U:.I./ml; 500 a 7.500 U.I./ml, respectivamente, sobre la formación de ácidos grasos volátiles, siguiendo el método "in vitro" de Tilley y Terry, con un sustrato de almidón, celulosa y urea (47,5, 47,5 Y 5 %) respectivamente. Los tres antibióticos son capaces de inhibir la producción total de ácidos grasos volátiles, siendo la Penilicina el menos eficaz. La Kanamicina y la Colistina aumentan la relación acético-propiónico pero no la Penicilina. Ninguno de los antibióticos ensayados tienen una acción beneficiosa sobre la produc.ción de ácido propiónico.The effect of three antíbiotics (Kanamycin, Penicillin and Colistin), at doses from 0,125 to 2,50 mg/ml; 50 to 1.000 U.I./ml; 500 to 7.500 U. I./ml, respectively) on the production of volatile fatty acids, has been studied according to the Tilley and Terry's method "in vitro", with a substract of starch, cellulose and urea (47,5, 47,5 and 5 %1) respectively. All three antibiotics are able to inhibit the total production of volatile fatty aCids, but Peniciline is the less effective. Kanamycin and Colistin increase the relation aetic-propionic, but Penicillin does noto None of the three tested antibiotics has a possitive effect on the propionic acid production

Influencia de la kanamicina, colistina y penicilina sobre la fermentación rumial “in vitro” de la urea

Se ha estudiado, empleando el método de fermentación ruminal "in vitro" de Tilley y Terry, el efecto sobre la fermentación de la urea de la Kanamicina, Colistina y Penicilina a dosis de 0,125 a 6,250 mg/ml, 500 a 15.000 U.L/mI y 50 a 2.500 U.L/mI. respectivamente. Los tres antibióticos a dosis altas reducen la cantidad fInal de nitrógeno precipitado, 10 que supone inhibición del crecimiento de la población microbiana, y aumentan la concentración de amoniaco. La eficacia de los antibióticos, a las dosis empleadas, es máxima para la Penicilina y mínima para la Kanamicina.The effect of Kanamycin, Colistin and Penicillin -using dosages from 0.125 up to 6.250 mg/mI; 500 up to 15.000 U.L/mI and 50 up to 2.500 U.L/mI respectively- over the fermentation of urea has been studied using the Tilley and Terry mmen fermentation "in vitro" method. Al1 of the three antibiotics at high dosages increase the ammonia concentration and reduce the fmal amount of precipitated nitro gen because of the inhibition of the microbial population growth. The effIciency of antibiotics at the used doses is maximal for Penicillin and minimal for Kanamycin

Effective Viscosity of Dilute Bacterial Suspensions: A Two-Dimensional Model

Suspensions of self-propelled particles are studied in the framework of two-dimensional (2D) Stokesean hydrodynamics. A formula is obtained for the effective viscosity of such suspensions in the limit of small concentrations. This formula includes the two terms that are found in the 2D version of Einstein's classical result for passive suspensions. To this, the main result of the paper is added, an additional term due to self-propulsion which depends on the physical and geometric properties of the active suspension. This term explains the experimental observation of a decrease in effective viscosity in active suspensions.Comment: 15 pages, 3 figures, submitted to Physical Biolog