Nueva sonda TDR para la medida de la conductividad eléctrica de la solución del suelo

Esta comunicación presenta una sonda TDR (WECP) para la medida de la conductividad eléctrica de la solución del suelo (σw), que consiste en una sonda TDR trifilar (10 cm longitud) insertadas en 14 discos cerámicos. La σw se estima a partir de la humedad y la conductividad eléctrica del conjunto de discos cerámicos. La WECP fue calibrada y testada en laboratorio con suelo franco y en condiciones de campo con diferentes soluciones de KCl. La σw estimada con WECP en laboratorio fue comparada con las obtenidas a partir de la solución de drenaje. El experimento de campo comparó σw estimados con WECP con los medidos con lisímetros de tensión. En ambos experimentos se observó una buena y significativa correlación (R2 ≥ 0,97; P < 0,001; Coeficiente de eficeincia Nash-Sutdiffe > 0,96) entre los valores de σw estimados con WECP y los obtenidos en laboratorio y campo a partir de la solución de drenajeEsta comunicación presenta una sonda TDR (WECP) para la medida de la conductividad eléctrica de la solución del suelo (σw), que consiste en una sonda TDR trifilar (10 cm longitud) insertadas en 14 discos cerámicos. La σw se estima a partir de la humedad y la conductividad eléctrica del conjunto de discos cerámicos. La WECP fue calibrada y testada en laboratorio con suelo franco y en condiciones de campo con diferentes soluciones de KCl. La σw estimada con WECP en laboratorio fue comparada con las obtenidas a partir de la solución de drenaje. El experimento de campo comparó σw estimados con WECP con los medidos con lisímetros de tensión. En ambos experimentos se observó una buena y significativa correlación (R2 ≥ 0,97; P < 0,001; Coeficiente de eficeincia Nash-Sutdiffe > 0,96) entre los valores de σw estimados con WECP y los obtenidos en laboratorio y campo a partir de la solución de drenajePublishe

Diversity and distribution of blackflies (Diptera: Simuliidae) of the Tormes river basin (western Spain)

To enhance the partial knowledge on blackfly (Diptera: Simuliidae) fauna in Spain it is crucial to collect all the available data on this group to better understand their ecology and distribution over the years. This study presents data from samples collected along the Tormes river basin (western Spain) during the years 1988, 1989 and 1996 and then stored at the University of Salamanca. As a result of a research stay, a total of 19 species belonging to 3 genera (Prosimulium, Metacnephia and Simulium) and 5 Simulium subgenera (Boophthora, Eusimulium, Nevermannia, Simulium and Wilhelmia) were identified after examining 64% of the stored material, representing 35% of the species known from Spain. In addition, 14 species are reported for the first time in 3 provinces in the study area. Further sampling of blackflies is foreseen in the near future in order to check if the blackfly fauna composition determined in samples collected during the last two decades of the 20th century has changed. This aim gains in importance as a consequence of haematophagous species having been found, relevant for both public health and animal welfare, not only because of the discomfort caused by their bites but also because of their potential as vectors of disease-causing agents in animals and humans

Applicability of the photogrammetry technique to determine the volume and the bulk density of small soil aggregates

Aggregate density (¿) is defined as the relationship between the mass and the volume occupied by an aggregate. Previous studies have characterised ¿ on large to medium-sized soil aggregates (>4mm diameter); however, little information is available for smaller aggregates (0.99, P<0.0001) between the volumes estimated on rough stones with the PHM and Archimedes methods demonstrates that this technique can be satisfactorily used to estimate the volume and, consequently, the ¿ of small soil aggregates. The results showed an increase in ¿ with decreasing aggregate size. A general trend of increasing ¿ with the degree of soil disturbance by tillage was also observed

On Iterated Twisted Tensor Products of Algebras

We introduce and study the definition, main properties and applications of iterated twisted tensor products of algebras, motivated by the problem of defining a suitable representative for the product of spaces in noncommutative geometry. We find conditions for constructing an iterated product of three factors, and prove that they are enough for building an iterated product of any number of factors. As an example of the geometrical aspects of our construction, we show how to construct differential forms and involutions on iterated products starting from the corresponding structures on the factors, and give some examples of algebras that can be described within our theory. We prove a certain result (called ``invariance under twisting'') for a twisted tensor product of two algebras, stating that the twisted tensor product does not change when we apply certain kind of deformation. Under certain conditions, this invariance can be iterated, containing as particular cases a number of independent and previously unrelated results from Hopf algebra theory.Comment: 44 pages, 21 figures. More minor typos corrections, one more example and some references adde

Environmental Fate of Terbuthylazine in Soils Amended with Fresh and Aged Final Residue of the Olive-Oil Extraction Process

ABSTRACT: The impact of de-oiled and dried two-phase olive mill waste (DW) amendment on the sorption, degradation, leaching, and persistence of the herbicide terbuthylazine in a Mediterranean agricultural soil were studied under laboratory and long-term field conditions. The results are compared with those of a previous study, where the intermediary by-product of the olive-oil processing technology (OW) was applied to the same soil. The adsorption of terbuthylazine by the soil significantly increased with the increase of the amount of DW in the laboratory and field-amended soils. The amount of terbuthylazine leached was significantly decreased or even not detected in the field-amended soil columns, but leaching losses of the herbicide increased by up to 52.7% in the laboratory amended-soils. The DW soil application significantly increased the half-life of terbuthylazine from 6.7 days for the original soil to 21 and 104 days in the field and laboratory amended soils, respectively. In the field study, DW addition decreased the vertical movement of terbuthylazine through the amended soils and increased the persistence of the herbicide in the upper 5 cm of the soils. This study suggests that DW amendment can play a positive role in preventing contamination of groundwater by terbuthylazine, especially after the transformation of the organic matter by aging processes. The results were quantitatively different from those previously obtained with the intermediary by-product OW, showing the importance of the specific characteristics of the amendment in determining its effect on pesticide environmental fate and behaviour

Field analysis of the deterioration after some years of use of four insect-proof screens utilized in Mediterranean greenhouses

The installation of insect-proof screens on greenhouse vents is one of the principal methods of protection against harmful insects for crops. Their main disadvantage lies on their negative effects on natural ventilation and greenhouse microclimate, which have been the focus of studies by several authors. However, few works have analysed the effect of accumulated dust and dirt on these screens. The present study has analysed four anti-insect screens, comparing their geometric characteristics before installation and after three to four years of use. Two negative effects have been observed and quantified: deterioration of the threads that make up the screen and reduction of porosity due to accumulated dirt in the pores. This deterioration over time gives leads to a mean increase in thread diameter of 3.1%, as well to a mean decrease in the pore size of 6.2% and 2.3% in the weft (Lpx) and the warp (Lpy), respectively. In fact, the insect-proof screen porosity (φ) decreased due to the deterioration of the threads by an average of 6.5%, in addition to an average 20.3% reduction due to the accumulation of dirt in the pores, making a total reduction in porosity of 26.8%. This decrease in porosity leads to lower greenhouse ventilation rates, and is therefore detrimental for the greenhouse microclimate. Consequently, it is recommended that insect-proof screens in arid areas such as Almería (Spain), with abundant dust suspended in the atmosphere, be washed monthly using water sprayed at high pressure

Pet ownership and health status of pets from immunocompromised children, with emphasis in zoonotic diseases

Q4Q4Artículo original205-210Objetive: To characterize pet ownership and pet health status in families of immunocompromised (IS) children, with emphasis in zoonotic diseases. Population and Methods: Families of IS children from two hospitals in San-tiago, Chile, were interviewed and their pets were evaluated by veterinary examination, coproparasitologic and skin dermatophytes test. In specifi c cases, other laboratory tests were performed in IS children or their relatives. Results: 47 out of 70 contacted families had pets, 42 participated in the study. Several risk factors for IS children were observed, as having a turtle as a pet and to clean cat or turtle faeces. Lack of adequate veterinary control, immunizations and deparasitation of pets were observed. Some animals showed zoonotic diseases or agents, as Brucella canis, Cryptosporidium sp, Giardia intestinalis, Toxocaracanis and scabies. 44% of dogs had ticks and 37% had fl eas, both potential vectors of infections. Conclusions: Our results suggest that policies to provide safer pet contact in IS children are needed

Mass-Up and Decision Peptide-Driven: two open-source applications for MALDI-TOF MS data analysis and protein quantification

Poster presentation at EUBIC Winter School 2017 (10th - 13th January 2017, Sporthotel Semmering, Austria)

Proxima Centauri b is not a transiting exoplanet

We report Spitzer Space Telescope observations during predicted transits of the exoplanet Proxima Centauri b. As the nearest terrestrial habitable-zone planet we will ever discover, any potential transit of Proxima b would place strong constraints on its radius, bulk density, and atmosphere. Subsequent transmission spectroscopy and secondary-eclipse measurements could then probe the atmospheric chemistry, physical processes, and orbit, including a search for biosignatures. However, our photometric results rule out planetary transits at the 200~ppm level at 4.5$~{\mu}m$, yielding a 3$\sigma$ upper radius limit of 0.4~R_\rm{\oplus} (Earth radii). Previous claims of possible transits from optical ground- and space-based photometry were likely correlated noise in the data from Proxima Centauri's frequent flaring. Follow-up observations should focus on planetary radio emission, phase curves, and direct imaging. Our study indicates dramatically reduced stellar activity at near-to-mid infrared wavelengths, compared to the optical. Proxima b is an ideal target for space-based infrared telescopes, if their instruments can be configured to handle Proxima's brightness.Comment: 8 pages, 3 figures, 2 tables, accepted for publication in MNRA