The impact of agroforestry combined with water harvesting on soil carbon and nitrogen stocks in central Chile evaluated using the ICBM/N model

Soil organic carbon (SOC) and total nitrogen (N) stocks in an agroforestry system with water harvesting were analysed in a field experiment and the results compared with those of other crop management systems in the Mediterranean zone of central Chile. Agroforestry with water harvesting showed higher positive effects on N stocks, mainly in the upper soil layer, than the other crop management systems. However, soil analysis revealed a lack of differences between treatments, a fact that might be related mainly to the short study time (12 years) and the high spatial variability in these soil properties at the experimental site. In addition, the Introductory Carbon Balance Model that simulates N processes (ICBM/N) was evaluated for simulating trends in SOC and N stocks in the field experiment. Soil data collected between 1996 and 2008 in the field experiment and primarily literature data sets were used to test ICBM/N and its performance was evaluated by considering uncertainty in model inputs using Generalised Likelihood Uncertainty Estimation (GLUE) methodology. The GLUE estimates (5% and 95%) and measured SOC and N stocks were in satisfactory agreement. The observed SOC and N stocks were bracketed by the uncertainty bands in 70% and 80% of the simulations, respectively. Sensitivity analysis showed the model to be most sensitive to C parameters, such as the humification coefficient (h). The results of this study show that ICBM/N can be an effective tool for estimating SOC and N stocks from agroforestry combined with water harvesting systems in the Mediterranean zone of central Chile over the medium term. However, they also indicate that additional data sets are needed to redefine the parameter distributions in the model and thus to predict trends in SOC and N stocks in the future.     

Residues of EBDC fungicides and ETU in experimental and commercial beverages (beer and wine)

Residues of EBDC (ethylenebisdithiocarbamate) fungicides and ETU (ethylenethiourea; 2-imidazolidinethione) were monitored in beers and wines from different locations. No EBDC residues were detected in any of the samples examined. Concerning the ETU residues, the residue levels higher than the limit of method detection (0.01 ppm) were 22.6% and 7.3% in the commercial beer and wine samples respectively, but the number of samples containing more than 0.1 ppm of ETU was practically negligeable.     

Degrees of vacuolation of the absorptive intestinal cells of five Sagitta (Chaetognatha) species: possible ecophysiological implications

The cell organization and ultrastructure of the intestine have been studied in five species of Sagitta, one epiplanktonic (S. bipunctata Quoy and Gaimard, 1827), four mesoplanktonic (S. megalophthalma Dallot and Ducret, 1969, S. decipiens Fowler, 1905, S. minima Grassi, 1881, S. zetesios Fowler, 1905). The intestinal epithelium is composed of two ciliated cell types. The first (S-cell) principally occurs in the anterior intestine and represents typical secretory cells. The second (A-cell) occurs in the median and posterior intestine and displays ultrastructural features involved in absorption and intracellular digestion, that is, coated pits, endocytotic vesicles, cytoplasmic tubules, and two distinct types of digestive vacuoles. Whereas S-cells exhibit few ultrastructural differences among the five species, the vacuolar volume of the A-cells located in the mid portion of the intestine is higher in the mesoplanktonic species. In S. zetesios and S. megalophthalma, each side of the median intestine comprises several hypervacuolated A-cells visible in transverse section; their degree of vacuolation is inversely proportional to their number. The increased volume of the intestinal vacuoles is most marked in S. decipiens and S. minima; in both these species, each lateral side of the median intestine displays a single ultravacuolated A-cell. The possible ecophysiological implications of intestinal vacuoles are discussed in relation to patterns of the vertical distribution of several Sagitta species. The vacuoles are presumed to regulate buoyancy, enabling the mesoplanktonic species to make vertical diel migrations. Received: 22 January 2000 / Accepted: 28 July 2000     

Comparative studies and evolution of muscles in chaetognaths

The chaetognath locomotory muscles exhibit astonishing variations. The secondary muscle, which represents less than 1% of the body wall, has two forms. One is unique in the animal kingdom (alternation of two sarcomere types: “classical cross-striated” s1 and a unique type, s2) and has already been described; it characterizes most of the genera. The other, found only in more or less benthic species, functions by supercontraction. In the primitive genus Archeterokrohnia, it often exhibits “s1/s2 hybrid” sarcomeres, appearing as s2 sarcomeres partly containing s1 ones; moreover, the alternation of s1 and s2 sarcomeres is not regular. New sarcomeres are formed by the splitting of the Z-discs between two consecutive s1 sarcomeres. This is another unique feature of the chaetognath secondary muscle which facilitates understanding the transition from the first to the second form: suppression of s2 sarcomeres and constitution of a supercontraction capability in s1 sarcomeres. The transverse muscle, present in the less evolved genera living near or on the bottom, also has two forms: either classical cross-striated or, in more or less benthic species, supercontracting. Supercontraction would be a derived character. The peculiarities of the primary, secondary and transverse muscles of the truly benthic chaetognaths are different from those of all the planktonic or benthoplanktonic chaetognaths. The variations in the histological and cytological characteristics of the muscles agree with the phylogenetic trends previously proposed for the phylum. Published online: 21 September 2002     

A SURVEY OF THE MICROBIAL QUALITY OF RECYCLED HOUSEHOLD GRAYWATER1

ABSTRACT: In arid regions where populations are expanding and water is scarce, people are searching for ways to conserve and reuse water. One way homeowners can conserve water is by recycling graywater‐wastewater from household sinks, showers, bathtubs, and washing machines. Graywater is used mostly for landscape irrigation. Since graywater is wastewater, reusing it raises concerns about disease transmission, either by contact with the water or the irrigated soil. The purpose of this study was to assess how factors such as number and age of household occupants, types of graywater storage, and sources of graywater used affect the microbial quality of graywater and soil irrigated with graywater. Samples were collected over twelve months from eleven Tucson, Arizona households recycling graywater. Samples of graywater, soil irrigated by graywater, and soil irrigated by potable water were collected. We found that graywater irrigation causes a statistically significant increase in levels of fecal coliforms in soil when compared to soil irrigated with potable water. Graywater from the kitchen sink significantly increases levels of these bacteria in water and soil. Children also cause a statistically significant increase in fecal coliform levels in graywater and soil, possibly introducing a small amount of additional risk in graywater reuse.     

Management of domoic acid monitoring in shellfish from the Catalan coast

Monitoring of amnesic shellfish poisoning (ASP) toxins in shellfish from the Catalan coast started in 2001. No ASP toxins were detected in any of the analyses performed before 2008. On 22 January 2008, domoic acid (DA) was detected in Donax trunculus (0.5 mg?kg^?1) and confirmed by rapid resolution liquid chromatography–tandem mass spectrometry (0.6 mg?kg^?1). A total of 974 shellfish samples were analyzed from January 2008 to December 2011, covering all the Catalan production areas and the most important marketed species. DA was detected in 23.8 % of the samples and was recorded every month in all areas and all species, except Ostrea edulis, although the percentage of samples with DA and DA content varied widely among samples. DA exceeded the regulatory level of 20 mg?kg^?1 twice: in Callista chione sampled on February 2008 and in D. trunculus sampled on April 2010. DA content in Bolinus brandaris appeared constant and close to 4.5 mg?kg^?1 for months in 2009. Mytilus galloprovincialis, Crassostrea gigas, and Ruditapes sp. presented very low concentrations of DA in the Ebro Delta bays, despite 113 alert situations according to Pseudo-nitzschia spp. abundances and the high number of shellfish samples analyzed. The origin of DA in Catalan shellfish remains unknown.     

Design and Application of Multi-layer Starch-Latex Blends as Phosphorous Delivery System

Journal of Polymers and the Environment - The search for highly productive agriculture has considerably increased the use of fertilizers, becoming a worrying source of environmental and health...     

Interrelationships of the two families constituting the Lophogastrida (Crustacea: Mysidacea) inferred from morphological and molecular data

The Lophogastrida are primitive Mysidacea and comprise only six genera. One of these, Eucopia is considered as highly specialized and constitutes the family Eucopiidae; the other genera constitute the Lophogastridae. Among the latter family, the genus Gnathophausia is closely related to Eucopia, with two species (G. gracilis and E. sculpticauda) sharing similar morphological characteristics [i.e. ornamentation (spines) of the uropods, and the gastric mill]. This indicates that these species are phylogenetically related. To test this hypothesis, the partial 16S mitochondrial ribosomal RNA gene from various representative species of Gnathophausia and Eucopia were compared. The resulting phylogenetic tree suggests that each genus is monophyletic, and that Gnathophausia, which is the deepest-branching genus, is the most primitive, with the Eucopiidae originating from the Lophogastridae. The molecular results support the morphological hypothesis, and suggest an early separation of the two genera or a rapid divergence of Eucopia due to morphological specialization. Received: 29 June 1997 / Accepted: 16 March 1998     

U-series disequilibria in a groundwater flow route as an indicator of uranium migration processes

U-series data relating to groundwater, fracture coatings and the adjoining rock matrix in a groundwater flow system at the Palmottu natural analogue site was examined. The aim was to obtain an experimental reference for migration modelling in a transport section defined within the flow system. The U-series reference obtained turned out to be a very useful tool for fine tuning the flow route and for migration mechanism considerations. The U-series data are well in line with other interpretations of the migration system.