Remoción de quistes de giardia duodenalis por filtración rápida

Con el objetivo de evaluar la remoción de quistes de Giardia duodenalis en agua, se construyó un filtro rápido por gravedad, a escala laboratorio, con arena (Tamaño efectivo: 0,95±0,03 mm) como material filtrante. El agua para la prueba de remoción (160 L) se preparó diluyendo una suspensión de quistes con H2Od hasta una turbiedad de 4 UNT. Para recuperar los quistes no removidos, el agua filtrada se pasó a través de membranas de nitrato de celulosa de 0,45 μm. El conteo de quistes se realizó en cámara de Neubauer. Mediante pruebas hidráulicas se estableció el espesor del lecho (0,75 m) y el tiempo de retención (5 min). La concentración de parásitos en el agua de entrada fue de 2,2 104 quistes/L, obteniéndose una remoción de 1,5 log (96,9 %). La turbiedad durante el periodo de filtración fue ≤ 1,22 UNT. Este trabajo confirma que aún en condiciones de filtración apropiadas, los quistes de Giardia pueden aparecer en el agua tratada cuando ocurre una elevada contaminación de la fuente.In order to evaluate the removal of cysts of Giardia duodenalis in water, a rapid gravity filter was constructed on laboratory scale with sand (effective size: 0.95 ± 0.03 mm) as a filter material. Water for the test (160 L) was prepared by diluting a suspension of cysts with H2Od until a turbidity of 4 UNT. To recover the unremoved cysts, the filtered water was passed through 0.45 μm cellulose nitrate membranes. The cysts count was performed in Neubauer chamber. The filter bed thickness (0.75 m) and the retention time (5 min) were established by hydraulic tests. The concentration of parasites in the incoming water was 2.2 104 cysts / L obtaining a removal of 1.5 log (96.9 %). The turbidity during the filtration period was ≤ 1.22 UNT. This investigation confirms that even under appropriate filtration conditions, cysts of Giardia can appear in the treated water when high source contamination occurs.Fil: Pizarro, A.. Universidad Nacional del LitoralFil: Zerbatto, M.. Universidad Nacional del LitoralFil: Pizarro, M.. Universidad Nacional del LitoralFil: Modini, L.. Universidad Nacional del Litora

Computational model of one-dimensional flow of water in an unsaturated soil

O estudo do fluxo de água em zonas não saturadas do solo é de grande importância para pesquisas relacionadas à disponibilidade hídrica para o desenvolvimento das plantas. Devido ao alto custo, ao tempo demandado e ao esforço humano nas investigações de campo, os modelos matemáticos, aliados às técnicas numéricas e avanços computacionais, constituem-se em uma ferramenta importante na previsão desses estudos. No presente trabalho, objetivou-se solucionar a equação diferencial parcial não linear de Richards mediante a aplicação do Método de Elementos Finitos. Na aproximação espacial, foi empregada a adaptatividade com refinamento "h" na malha de elementos finitos e, na derivada temporal, foi aplicado o esquema de Euler Explícito. A função interpolação polinomial utilizada foi de grau 2, e a que garantiu a conservação de massa da estratégia de adaptação. Para a validação do modelo, foram utilizados dados disponíveis em literatura. A utilização da função interpolação polinomial de grau 2 e o refinamento "h", com considerável redução do tempo de execução da rotina computacional, permitiram uma boa concordância do modelo em comparação a soluções disponíveis na literatura.Study of water flow in the unsaturated soil zone is of great importance for research related to the water availability for crop development. Due to the high cost, the time required and the human effort in the field investigations, mathematical models combined with numerical techniques and computational advances are important tools in the prediction of these studies. This work aimed to solve the Richards's non-linear partial differential equation by applying the Finite Element Method. Adaptability with "h" refinement of the finite element mesh was used in the spatial approximation, while Explicit Euler scheme was applied for the time derivative. The polynomial interpolation function used was of degree two, and ensured the mass conservation of the adaptation strategy. To validate the model, data available in the literature were used. Use of the polynomial interpolation function with degree two and the "h" refinement, with considerable reduction of the computational runtime allowed good agreement in comparison to solutions available in the literature

Aportación al conocimiento del ciclo biológico de Chromulina nevadensis

En este trabajo se amplía y se comenta la descripción de Chromulina nevadensis P.M. Sánchez. El estudio se realiza en una laguna oligotrófica de alta montaña (La Caldera), próxima a la laguna de Aguas Verdes, donde se obtuvo el material para su descripción original.Igualmente realizamos algunas consideraciones sobre el comportamiento mixotrófico de este taxon, ya conocido para otros miembros de las crisofíceas. Para finalizar describimos, por primera vez, la morfología a MEB de su estatosporaIn this paper we present data about enlargement of the original description of Chromulina nevadensis. This study has been carried out on an oligotrophic high mountain lake (La Caldera) close to the lake where it was described (Aguas Verdes). Also we make some consideration about the mixotrophy, a nutritional behavior previously knew for other chrysophyceae taza. Finally we study, by the first time, the morfology of its statospores with SEM

Phytoplankton patchiness in two shallow waterbodies

The hydrodynamic behaviour in lentic ecosystems is closely related with the spatial and temporal evolution of their physical, chemical and biological characteristics. Because of this, and in order to improve our present knowledge on the limnological dynamics of such ecosystems, a coupled analysis on the relationship between the biological patterns and the governing hydrodynamics mechanisms it is necessary. This paper uses both field analysis and numerical simulation to describe the links between the water movements and the phytoplankton spatial distribution on two shallow waterbodies in the South of Spain: Alhama de Granada Reservoir (Granada) and Laguna Nueva de la Albufera de Adra (Almería). In both systems the observed phytoplankton spatial distribution exhibited dynamic patterns forced by hydrodynamical transport processes. The knowledge of this physical-biological coupling could be useful to outline the basic guidelines for water quality management.Los ecosistemas acuáticos leníticos se caracterizan por un intenso acoplamiento entre los mecanismos de transporte hidrodinámico que en ellos ocurren y la evolución espacial y temporal de sus principales variables físico-químicas y biológicas. En consecuencia y con el objetivo de mejorar nuestro entendimiento sobre la dinámica limnológica de este tipo de sistemas, resulta necesario el desarrollo de análisis interdisciplinares que profundicen en esta estrecha relación hidrodinámica-biología. En este trabajo se analiza, a partir de estudios de campo y simulaciones numéricas, el acoplamiento entre el movimiento de la masa fluida a nivel de macroescala y la distribución espacial del fitoplancton en dos ecosistemas acuáticos someros del Sur de España : el embalse de Alhama de Granada (Granada) y la Laguna Nueva de la Albufera de Adra (Almería). En ambos sistemas se han encontrado patrones dinámicos de distribución espacial de las microalgas, íntimamente relacionados con la dinámica de la masa de agua. El conocimiento de este acoplamiento resulta útil en la definición de líneas básicas para la adecuada gestión de la calidad del agua

Hoteling cruise ship's power requirements for high voltage shore connection installations

The main objective of this paper is the presentation of a theoretical and quantitative study of the power requirements that any port considering to install and develop shore to ship connection systems must consider. Particularly, the current study focuses these requirements for cruise ship ports and their terminals. This paper provides theoretical and quantitative tools and ideas that can be used to estimate main design parameters such as frequency, voltage and power for high voltage shore connections. Some models and equations are developed aiming to be able to estimate, with acceptable quality, cruise ship’s power demand for hoteling services at port. On the other hand, this article is intended to assess ship's air pollution impact populated harbour areas to decide whether alternative power supply measures are feasible. Finally, the assessment model is applied at Barcelona's cruise piers and case study is discussed. As a result of that, a daily power demand curve and the consequent air pollution study at the most crowded situation in this port are obtained.Postprint (published version

Automated detection of fluorescent cells in in-resin fluorescence sections for integrated light and electron microscopy

Integrated array tomography combines fluorescence and electron imaging of ultrathin sections in one microscope, and enables accurate high-resolution correlation of fluorescent proteins to cell organelles and membranes. Large numbers of serial sections can be imaged sequentially to produce aligned volumes from both imaging modalities, thus producing enormous amounts of data that must be handled and processed using novel techniques. Here, we present a scheme for automated detection of fluorescent cells within thin resin sections, which could then be used to drive automated electron image acquisition from target regions via 'smart tracking'. The aim of this work is to aid in optimization of the data acquisition process through automation, freeing the operator to work on other tasks and speeding up the process, while reducing data rates by only acquiring images from regions of interest. This new method is shown to be robust against noise and able to deal with regions of low fluorescence

The Relative Age Effect on Soccer Players in Formative Stages with Different Sport Expertise Levels

The Relative Age Effect (RAE) in sport has been targeted by many research studies. The objective of this study was to analyze, in amateur clubs, the RAE of soccer players, according to the sport expertise level of the team (e.g., A, B, C and subsequent) that they belong to within the same game category. 1, 098 soccer players in formative stages took part in the study, with ages varying between 6 and 18 years old (U8 to U19 categories). All of them were members of 4 Spanish federated clubs. The birth dates were classified into 4 quartiles (Q1 = Jan-Mar; Q2 = Apr-Jun; Q3 = Jul-Sept; Q4 = Oct-Dec)according to the team they belonged to. The results obtained in the chi-squared test and d value (effect size) revealed the existence of RAE in the teams with the highest expertise level, "A" (X2 = 15.342, p = .002, d = 0.4473) and "B" (X2 = 10.905, p = .012, d = 0.3657). However, in the lower level teams, "C and subsequent", this effect was not observed. Present findings show that players born during the first months of the year tend to be selected to play in teams with a higher sport expertise level of each category, due to their physical maturity. Consequently, this causes differences in terms of the experience they accumulate and the motivation that this creates in these players