Site-specific chlorophyll reference conditions for lakes in Northern and Western Europe

The Water Framework Directive (WFD) requires EU Member States to assess the “ecological status” of surface waters. As a component of ecological status, many European countries are developing a classification scheme for chlorophyll concentrations as a measure of phytoplankton biomass. The chlorophyll classification must be based on the degree of divergence of a water body from an appropriate baseline, or ‘reference condition’. This paper describes the development of a series of regression models for predicting reference chlorophyll concentrations on a site-specific basis. For model development a large dataset of European lakes considered to be in reference condition, 466 lakes in total, was assembled. Data were included from 12 European countries, but lakes from Northern and Western Europe dominated and made up 92% of all reference lakes. Data have been collated on chlorophyll concentration, altitude, mean depth, alkalinity, humic type, surface area, and geographical region. Regression models were developed for estimating site-specific reference chlorophyll concentrations from significant predictor ‘typology’ variables. Reference chlorophyll concentrations were found to vary along a number of environmental gradients. Concentrations increased with colour and alkalinity, and decreased with lake depth and altitude. Forward selection was used to identify independent explanatory variables in regression models for predicting site-specific reference chlorophyll concentrations. Depth was selected as an explanatory variable in all models. Alkalinity was included in models for low colour and humic lakes and altitude was included in models for low colour and very humic lakes. Uncertainty in the models was quite high and arises from errors in the data used to develop the models (including natural temporal and spatial variability in data) and also from additional explanatory variables not considered in the models, particularly nutrient concentrations, retention time and grazing. Despite these uncertainties, site-specific reference conditions are still recommended in preference to type-specific reference conditions, as they use the individual characteristics of a site known to influence phytoplankton biomass, rather than adopt standards set to generally represent a large population of lakes of a particular type. For this reason, site-specific reference conditions should result in reduced error in ecological status classifications, particularly for lakes close to typology boundaries

Genome-wide identification, and characterization of the CDPK gene family reveal their involvement in abiotic stress response in Fragaria x ananassa

Abstract Calcium-dependent protein kinases (CDPKs) are encoded by a large gene family and play important roles against biotic and abiotic stresses and in plant growth and development. To date, little is known about the CDPK genes in strawberry (Fragaria x ananassa). In this study, analysis of Fragaria x ananassa CDPK gene family was performed, including gene structures, phylogeny, interactome and expression profiles. Nine new CDPK genes in Fragaria x ananassa were identified based on RNA-seq data. These identified strawberry FaCDPK genes were classified into four main groups, based on the phylogenetic analysis and structural features. FaCDPK genes were differentially expressed during fruit development and ripening, as well as in response to abiotic stress (salt and drought), and hormone (abscisic acid) treatment. In addition, the interaction network analysis pointed out proteins involved in the ABA-dependent response to plant stress via Ca2+ signaling, especially RBOHs. To our knowledge, this is the first report on CDPK families in Fragaria x ananassa, and it will provide valuable information for development of biofortified fruits and stress tolerant plants

Características físico-químicas e sensoriais de batata frita da cultivar BRS Ana branqueada e revestida com metilcelulose

Resumo O estudo propôs avaliar o efeito do branqueamento combinado ao uso de sais e de revestimentos à base de metilcelulose (MC) na absorção de gordura e nas características físico-químicas e sensoriais de batatas da cultivar BRS Ana, submetidas à fritura na forma de batata chips. O experimento foi realizado com a cultivar BRS Ana e a cultivar Asterix, sendo a batata Asterix adequada para produtos fritos. Para o estudo foram definidos controles para as batatas das cultivares BRS Ana (T0’) e Asterix (T0”), batatas que não foram submetidas ao branqueamento nem a qualquer tipo de revestimento. Foram testados três tratamentos para cada cultivar; para a cultivar BRS Ana: T1: com branqueamento e sem revestimento; T2: com branqueamento e com revestimento de 1% de MC; T3: com branqueamento e com revestimento de 2% de MC; para a cultivar Asterix: T4: com branqueamento e sem revestimento; T5: com branqueamento e com revestimento de 1% de MC; T6 com branqueamento e com revestimento de 2% de MC. Para os tratamentos que receberam o branqueamento (T1, T2, T3, T4, T5 e T6), foi realizada uma imersão das fatias de batata em água a 85 ºC por 3 minutos, com adição de 0,5% de CaCl2 e 2,5% de NaCl, seguida de resfriamento e centrifugação. As batatas dos tratamentos T2, T3, T5 e T6 que receberam revestimento de MC foram imersas em solução de MC 1 ou 2% (p/v), por 1 min e, em seguida, drenadas. As batatas foram submetidas à fritura em gordura vegetal a 180 ºC. A maior redução de absorção de gordura (13%) durante a fritura foi para batata da cultivar BRS Ana submetida ao branqueamento e revestimento com 1% MC, obtendo-se no produto final 29,37% de gordura. Além disso, o revestimento com 1% MC não modificou significativamente a cor e a textura das batatas chips; nos resultados sensoriais esse tratamento não influenciou na preferência para os atributos testados (aparência, cor, sabor e textura) e o índice de aceitação sensorial desse tratamento foi de 85,9%. A batata da cultivar BRS Ana submetida ao branqueamento adicionado de NaCl e CaCl2 e revestimento com 1% de MC apresenta potencial de utilização na forma de batata chips

Assessment of the ecological status of European surface waters: a work in progress

The 'normative definitions' of ecological water quality classes given by the Water Framework Directive (WFD) are narrative descriptions of the conditions present in water bodies of different qualities relative to reference conditions found in unimpacted sites. In order to fill these descriptions with a more solid content, the definitions have been a subject of intensive development of quantitative methodologies for ecological status assessment as well as for rules and criteria for setting of reference conditions and ecological status boundaries for classification of water bodies. In this article, we recall the basic principles of the WFD that sometimes have been overlooked and point out some gaps remained and problems arisen during the ongoing implementation of the directive. Defining type-specific reference conditions for water bodies and finding biological metrics that sensitively reflect only the anthropogenic deviations from those conditions are the biggest challenges that the ecological status assessment faces. So far, there is no guarantee that reference conditions are comparable across EU Member States due to a lack of common criteria, which need still to be elaborated. Defining site-specific reference conditions instead of type specific is a novel approach that allows for minimizing uncertainties introduced by applying broad types. Search for new metrics has led to a real boom of multimetric indices which ought to be the adequate tool to measure the multiple human impairments but which should pass a thorough check before being included in monitoring programs. Curiously, some biological indices constructed as surrogates for chemistry (especially nutrients) start 'living their own life' and continue indicating the disturbance when the controlling factors change. This shows the obvious advantage of biological indicators against chemical ones. New challenges to WFD implementation are brought about by the need to consider the effects of alien species and climate change in the assessment framework, and by the nonlinear dose-response relationships dominating in biological systems. Attempts to diminish uncertainties in quality assessment have become a new labour-intensive field for researchers