Estimating the Self-depuration Capacity of a Reach of the Luján River

A 3-km reach of the Luján River was studied by establishing 6 sampling stations, which were from 300 to 500 m apart. The first station was the control reading for river nutrients and particulate material. The second station measured the continuous effluent from a wastewater treatment plant flow of the city of Luján and was, therefore, considered a continuous addition point of nutrients. The other 4 stations were used to evaluate whether the river captured phosphorus as phosphate, nitrogen as ammonium, nitrite or nitrates, and the suspended particulate material, both organic and inorganic. These data were used to calculate material uptake (U), uptake velocity (Vf), and net distance Snet under two different hydrological situations, during low and high flow, during the same season of the same year. Results indicate that phosphate ions as well as organic matter are retained for less than 2 km in both high and low flow situations. In the case of ammonium, the results appear similar to those of phosphate ions but it may be transformed into nitrates and transported in the latter form for greater distances. It is concluded that this river, in the reach under study, has a variable retention speed according to its flow but the retention capacity is no less than 900 m and as much as 2000 m. Therefore, a 2 km distance must be considered as the minimum distance before another effluent of nutrients or organic matter is added.Fil: Piccinini, Mauricio. Provincia de Buenos Aires. Municipalidad de Lujan; ArgentinaFil: Sánchez Caro, Anibal. Universidad Nacional de Luján. Instituto de Ecología y Desarrollo Sustentable. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ecología y Desarrollo Sustentable; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Gultermiriam, M.L.. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Giorgi, Adonis David Nazareno. Universidad Nacional de Luján. Instituto de Ecología y Desarrollo Sustentable. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Ecología y Desarrollo Sustentable; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Two Amino Acid Changes at the N-Terminus of Transmissible Gastroenteritis Coronavirus Spike Protein Result in the Loss of Enteric Tropism

AbstractTo study the molecular basis of TGEV tropism, a collection of recombinants between the PUR46-MAD strain of transmissible gastroenteritis coronavirus (TGEV) infecting the enteric and respiratory tracts and the PTV strain, which only infects the respiratory tract, was generated. The recombinant isolation frequency was about 10−9recombinants per nucleotide and was 3.7-fold higher at the 5′-end of the S gene than in other areas of the genome. Thirty recombinants were plaque purified and characterized phenotypically and genetically. All recombinant viruses had a single crossover and had inherited the 5′- and 3′-halves of their genome from the enteric and respiratory parents, respectively. Recombinant viruses were classified into three groups, named 1 to 3, according to the location of the crossover. Group 1 recombinants had the crossover in the S gene, while in Groups 2 and 3 the crossovers were located in ORF1b and ORF1a, respectively. The tropism of the recombinants was studied. Recombinants of Group 1 had enteric and respiratory tropism, while Group 2 recombinants infected the respiratory, but not the enteric, tract. Viruses of both groups differed by two nucleotide changes at positions 214 and 655. Both changes may be in principle responsible for the loss of enteric tropism but only the change in nucleotide 655 was specifically found in the respiratory isolates and most likely this single nucleotide change, which leads to a substitution in amino acid 219 of the S protein, was responsible for the loss of enteric tropism in the closely related PUR-46 isolates. The available data indicate that in order to infect enteric tract cells with TGEV, two different domains of the S protein, mapping between amino acids 522 and 744 and around amino acid 219, respectively, are involved. The first domain binds to porcine aminopeptidase N, the cellular receptor for TGEV. In the other domain maps a second factor of undefined nature but which may be the binding site for a coreceptor essential for the enteric tropism of TGEV

Performance and emissions of an agricultural diesel engine fuelled with different diesel and methyl ester blends

This paper shows the results of an investigation carried out to assess the application of different fuels produced by blending diesel fuel with methyl ester obtained from mixture of 75% (v/v) sunflower oil and 25% (v/v) used cooking oil on a Kubota agricultural indirect injection diesel engine, natural aspirated, and with a rated horsepower of 19.7 kW. Seven fuels, namely diesel fuel; 90:10, 80:20, 70:30, 50:50, 25:75 and 0:100 (%v/v) blends were prepared and tested for the performance of the diesel engine in accordance with the standardised OECD test code 2. The test results showed that the performance of the engine was satisfactory without a significant reduction in power output and torque with blends smaller than 50%. Fuel consumptions with biodiesel were higher than that when fuelled with diesel but differences were not very marked up to 30% blends. As the reduction of the engine thermal efficiency was less than the corresponding reduction in heating value of the different biodiesel blends, the latter resulted in a more complete combustion in comparison with diesel fuel. The oxides of nitrogen (NOx) emissions were found to be reduced as the biodiesel concentration increase, particularly with 70% and 100% blends. The emissions of carbon monoxide (CO) were lower and increased at a lower rate with the oxygen concentration of the exhaust as the biodiesel blends were equal or higher than 50%

Engineering Final Project supervised in an adaptive way with Moodle support

For the current Engineering degrees, it’s necessary to design a monitoring process in order to supervise the subject called “Final Degree Project”. This method must be able to manage and evaluate the process of completing the project and submitting the documentation. This paper describes the design of an adaptive method and how to put this mechanism into practice using the learning management system Moodle. Adaptivity provides the chance to study different scenarios that can be produced in cooperation with students and their tutors. The conclusions of this work show a high level of satisfaction with the adaptive method used in the subject

Fatty acid composition of Mytilus galloprovincialis larvae fed on different micoralgal diets: effect on larval growth and survival.

The influence of dietary essential fatty acid on bivalve larval growth and survival has been reported by several authors. The objectives of the current research were (1) to describe fatty acid composition of Mytilus galloprovincialis D-larvae and (2) to investigate the influence of algal lipid composition on larval growth and survival. Larvae were fed with two diets, A (Tetraselmis suecica + Isochrisis galbana) and B (Tetraselmis suecica + Chaetoceros sp). After fifteen days the larval growth was significantly higher with diet B than with diet A. The survival was also different, being 28% in diet A and 22.4 % in diet B. The percentages of veliger, pediveliger and amorphous larvae were higher in group A than in B, while in the latter there were not amorphous larvae and the 21 % were postlarvae. So, the microalgae Chaetoceros sp seems to enhance larvae growth and development. The difference in diet also produced changes in fatty acid profiles being the most important change ones (1) the increase of 14:0 in both groups, (2) 16:0 decreased in group A but it increased in group B and (3) total MUFA showed higher levels in both trials. Total PUFA n-6 level was higher in group A due to the 18:2n-6 increase. Arachidonic acid level was augmented with both diets. EPA level diminished in group A but it augmented in group B, DHA behaviour was opposite, increasing in group A but decreasing in group B. This is due to the high level of EPA in Chaetoceros sp and DHA in Isochrysis galbana (Fern&aacute;ndez-Reiriz et al., 2006). These results do not coincide with other studies which suggest that DHA is a key requirement for larval development and growth of other bivalve species (Caers et al., 1999). In our case diet rich in EPA seems to be better in mussel larva culture than the diet rich in DHA. This work was supported by Interreg Project 0251_ECOAQUA_5_E, financed by the EDRF (European Regional Development Fund). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua. &nbsp;La influencia de la composici&oacute;n en &aacute;cidos grasos de la dieta ha sido estudiada por diversos autores. Los objetivos de este trabajo fuero (1) describir la composici&oacute;n en &aacute;cidos grasos de las larvas D de Mytilus galloprovincialis y (2) investigar la influencia de la composici&oacute;n lip&iacute;dica de las microalgas en el crecimiento y supervivencia larvario. Las larvas se fueron alimentadas con dos dietas,A (Tetraselmis suecica + Isochrisis galbana) y B (Tetraselmis suecica + Chaetoceros sp). Tras quince d&iacute;as el crecimiento larvario fue significativamente mayor con la dieta B que con la dieta A. La supervivencia tambi&eacute;n fue diferente, siendo 28 % en la dieta A y 22.4% en la dieta B. El porcentaje de las larvas veliger, pediveliger y amorfas fue mayor en A que en B, mientras que en &eacute;ste no hubo amorfas y el 21 % fueron postlarvas. Por lo tanto la microalga Chaetoceros sp mejora el cultivo larvario. La diferencia en la dieta tambi&eacute;n produjo cambios en el perfil de &aacute;cidos grasos siendo los m&aacute;s importantes (1) el incremento del 14:0 en ambos grupos, (2) el 16:0 decreci&oacute; en el grupo A pero aument&oacute; en el B y (3) el total de monoinsaturados mostr&oacute; mayores valores en ambos grupos. El total de PUFA n-6 fue mayor en el grupo A debido al incremento de 18:2n-6. El nivel de &aacute;cido araquid&oacute;nico aument&oacute; en ambos grupos. El nivel de EPA disminuy&oacute; en el grupo A pero aument&oacute; en el grupo B, el comportamiento del DHA fue el contrario, incrementando en el grupo A y disminuyendo en el B. Esto fue debido al alto nivel de EPA en Chaetoceros sp y DHA en Isochrysis galbana (Fern&aacute;ndez-Reiriz et al., 2006). Estos resultados no coinciden con otros estudios que sugieren que el DHA es un requerimiento clave para el desarrollo y crecimiento larvarios de otras especies de bivalvos (Caers et al., 1999). En nuestro caso la dieta rica en EPA parece ser mejor para el cultivo larvario de mejillones que la dieta rica en DHA. Este trabajo fue apoyado por el proyecto Interreg 0251_ECOAQUA_5_E, financiado por el FEDER (Fondo Europeo de Desarrollo Regional). www.juntadeandalucia.es/agriculturaypesca/ifapa/ecoaqua.</p

Component-Resolved in Vitro Diagnosis in Peach-Allergic Patients

BACKGROUND: The in vitro diagnosis of pollen-related food allergy presents low specifi city and reproducibility with many conventional extracts. This can be improved using natural purifi ed allergens, recombinant purifi ed allergens, or both. OBJECTIVE: We compared specifi c immunoglobulin (Ig) E determination (sIgE), the basophil activation test (BAT), the histamine release test (HRT), and the cellular allergen stimulation test (CAST) using natural and recombinant allergens in the diagnosis of peach allergy. METHODS: Thirty-two peach allergic patients were studied. Skin prick tests were performed with commercial peach and extract with Mal d 1, nPru p 3, and profi lin (nPho d 2). sIgE, BAT, CAST, and HRT were determined using rPru p 3, rMal d 3, rBet v 1, rMal d 1, and rMal d 4. RESULTS: Agreement between the techniques was good with all the allergens, except HRT with rMal d 1 and rMal d 4. With rPru p 3, sIgE, CAST, BAT, and HRT showed sensitivity values of 88%, 81%, 72%, and 69% and specifi city values of 100%, 93%, 97%, and 83%, respectively. In patients with systemic symptoms or contact urticaria, the values were 100%, 85%, 81%, and 81%. In patients with oral allergy syndrome, sensitivity to profi lins or homologues of Bet v 1 was detected in 100% of the cases by all the techniques, except by HRT with rMal d 1, which detected 66% of the cases. CONCLUSIONS: The use of single allergens in the in vitro diagnosis of peach allergy by specifi c IgE determination, BAT, and CAST offers high specifi city and sensitivity, with better results than the HRT

Ventajas e inconvenientes de la asistencia obligatoria a “Fisiología de la Digestión”, una asignatura de posgrado

Objetivos: Los criterios de evaluación actuales deben valorar no solo la adquisición de habilidades cognitivas que facilitan la asimilación progresiva de los contenidos, sino también de competencias específicas para el desarrollo de su formación profesional. Así, en este trabajo se analizan las ventajas e inconvenientes de la asistencia diaria obligatoria con respecto a la asistencia libre, como un criterio de evaluación para la asignatura de Posgrado Fisiología de la Digestión del Máster Universitario de Fisiología y Neurociencia de la Universidad de Sevilla. Material y Métodos: Se han comparado las calificaciones obtenidas por los alumnos de la asignatura de posgrado Fisiología de la Digestión durante dos cursos académicos (cursos 2010-2011, 2011-2012), donde la asistencia a clase fue obligatoria y los siguientes cursos (2012-2013, 2013-2014), donde dejó de tenerse en cuenta este criterio. Resultados y Discusión: Los alumnos con asistencia obligatoria no acudieron más a clase que los alumnos con asistencia libre y presentaron un porcentaje menor de calificaciones con sobresalientes y notables. Además, estos alumnos presentaron alrededor de un 5% de suspensos en comparación a los de asistencia libre, que nunca suspendieron. Finalmente, los alumnos de este último grupo participaron en las actividades de innovación con mayor interés. Conclusiones: En base a estos resultados se puede sugerir que durante los estudios de posgrado, la asistencia obligatoria disminuyó el interés y el rendimiento de los alumnos, mientras que la asistencia libre fomentó la participación en clase y en las actividades de innovación complementarias, mejorando sus calificaciones, por tanto la asistencia obligatoria no es un buen criterio de evaluación para la asignatura Fisiología de la Digestión.Aim: The current evaluation criteria assess not only the acquisition of cognitive skills that facilitate the gradual assimilation of the contents, but also specific responsibilities to develop the professional profile. Therefore, in this study we analyzed advantages and disadvantages of obligatory daily attendance respect to free for the postgraduate subject Physiology of the digestion of the Master Physiology and Neuroscience of the University of Seville. Material and Methods: We compared the scores of students in the postgraduate subject of Physiology of Digestion during two academic courses (courses 2010-2011 and 2011-2012), with obligatory attendance, and the two following courses (2012-2013 and 2013-2014) where this criterion was not evaluated. Results and Discussion: Students with obligatory attendance didn’t attended more to class that their free attendance partners; they even had a lower percentage of maximum qualifications. These students presented about a 5% of failing grades. When attendance was free, students didn’t fail and participated with more interest in innovation activity. Conclusions: According to these results, we could suggest that in postgraduate studies the mandatory attendance decreased the interest and efficiency of students. However, the free attendance promoted participation in class and in complementary innovation activity, and it also improved the qualifications of students. Therefore, mandatory attendance is not a good evaluation criterion for the subject of Physiology of Digestio

Magnetic-field symmetries of mesoscopic nonlinear conductance

We examine contributions to the dc-current of mesoscopic samples which are non-linear in applied voltage. In the presence of a magnetic field, the current can be decomposed into components which are odd (antisymmetric) and even (symmetric) under flux reversal. For a two-terminal chaotic cavity, these components turn out to be very sensitive to the strength of the Coulomb interaction and the asymmetry of the contact conductances. For both two- and multi-terminal quantum dots we discuss correlations of current non-linearity in voltage measured at different magnetic fields and temperatures.Comment: 9 pages, 4 figure

Self-learning didactic resources for the teaching of haematology in the faculty of pharmacy at the University of Seville

El objetivo principal de este trabajo es fomentar el autoaprendizaje y la relación profesor-alumno. Esto lo conseguiremos promoviendo el seguimiento continuado del alumno mediante tutorías presenciales y virtuales, y la evaluación de varios temas del programa seleccionados por el profesor para ser abordados por los alumnos. La materia elegida, Hematología, forma parte de la Licenciatura de Farmacia. Este proyecto, dirigido a 400 alumnos, ha pretendido darles las bases metodológicas suficientes para elaborar un trabajo de calidad, mediante el desarrollo escrito de varios temas del programa, concretando la información, distinguiendo lo más importante de cada tema, participando en el desarrollo continuo de la materia, utilizando las tutorías como fuentes de información y mejorando sus calificaciones y autoaprendizaje. Como resultado mas importante a destacar de esta actividad, encontramos un elevado grado de participación por parte de los alumnos, que valoraron muy positivamente la experiencia. Como reflejo de esta satisfacción los resultados académicos mejoraron sustancialmente, hecho constatado al comparar las tasas de rendimiento y éxito respecto a las existentes de manera previa a la implantación de esta actividad de innovación.The main aim of this project is to stimulate the creation of self-learning material and to improve the relationship between teachers and students. This will be achieved through the construction of a lesson of the theoretical program, by the student him- or herself. Part of the Pharmacy Degree course, Haematology, was the chosen subject. This work has been undertaken with 400 students distributed in 4 groups. They received sufficient methodological grounding to produce a high quality work, promoting their expression capacity, along of the realization of a lesson of the program, thus defining information; distinguishing the most important areas in each subject; participating in the continuous development of the material; promoting the tutorship and improving their marks and self-learning. The main result of the innovation show the students’ high level of participation in the activity, which was evaluated as a very positive innovation activity. Furthermore, as the performance rate compared with previous years illustrates, academic results have improved greatly

Aplicación de quitosano modificado en el tratamiento de aguas residuales de tenerías

In this study, the adsorption capacity of chromium VI in copper-modified chitosan (Chitosan-Cu) and in zinc-modified chitosan (Chitosan-Zn), and its application in tannery wastewater were compared. This work included the study of the pH of maximum adsorption capacity in a range of 3 to 6 and the adsorption equilibrium of Cr (VI) at different concentrations (from 1.0 to 750.0 mg / l) and different masses of modified bio-adsorbents (5 and 2 g). The results showed that the adsorption of chromium VI in the two modified bioadsorbents depends strongly on the pH of the solution, where the highest percentage of chromium VI removal was reached at pH 3. The evaluation of the data Experiments of the adsorption equilibrium of Cr (VI) applying the Langmuir and Freundlich models shows that in all cases there was a better fit of the data to the Freundlich model and that the maximum adsorption capacity was reached in the Chitosan-Cu adsorbent. Also, the results indicated that the Chitosan-Cu adsorbent was more effective in the removal of Cr VI from tannery wastewater with 98%.En este estudio se comparó la capacidad de adsorción de cromo VI en quitosano modificado con cobre (Quitosano–Cu) y en quitosano modificado con cinc (Quitosano–Zn), y su aplicación en aguas residuales de tenería. Este trabajo incluyó el estudio del pH de máxima capacidad de adsorción en un rango de 3 a 6 y el equilibrio de adsorción de Cr (VI) a diferentes concentraciones (de 1.0 a 750.0 mg/l) y diferentes masas de bio-adsorbentes modificados (5 y 2 g). Los resultados muestran que la adsorción del ion metálico en los dos bio-adsorbentes modificados depende fuertemente del pH de la solución, donde el mayor porcentaje de remoción de cromo VI se alcanzó a pH 3. Por su parte, la evaluación de los datos experimentales del equilibrio de adsorción de Cr (VI), aplicando los modelos de Langmuir y Freundlich, mostró que en todos los casos hubo un mejor ajuste de los datos al modelo de Freundlich y que la capacidad máxima de adsorción fue alcanzada en el adsorbente Quitosano–Cu. Así también, los resultados indicaron que el adsorbente Quitosano–Cu fue más efectivo en la remoción de Cr VI de las aguas residuales de tenería con un 98%