Reliability analysis of fish traits reveals discrepancies among databases

1. Trait-based approaches are commonly used in ecology to understand the relationship between biodiversity and ecosystem functioning, environmental filtering or biotic responses to anthropogenic perturbations. However, little is known about the reliability of assigned traits and the consistency of trait information among different databases currently in use.
2. Using 99 native and alien Iberian inland fish species, we investigated a total of 27 biological and ecological traits for their consistency among 19 different databases and identified less reliable traits, that is, traits with high disagreement among databases. Specifically, we used generalised linear models and inter-rater reliability statistics (Krippendorff's α) to test for differences in trait values among databases. We also identified well-studied versus data-deficient traits and species.
3. Our results show notable discrepancies and low reliability for several biological and ecological traits such as microhabitat preference, omnivory, invertivory, rheophily, and limnophily. Least reliable traits were mainly categorical (rather than continuous) and established by expert judgment and without a clear definition or a common methodology. Interestingly, categorical traits such as rheophily or limnophily, which showed significantly lower reliability, concurrently showed higher data availability and use than continuously scaled traits.
4. Such uncertainties in trait assignments could affect bioassessment and other ecological analyses. Species with smaller distributional ranges and those that have been described more recently, presented lower coverage and data availability in trait databases.
5. We encourage further standardisation of fish trait measurement protocols to help improve the robust application of bioassessment indices and trait-based approaches.

     

Triple density molecular quantum similarity measures: A general connection between theoretical calculations and experimental results

A newquantum similarity measure is defined. It is proposed as a way to project density functions from infinite dimensional spaces, where density functions belong, to finite dimensional ones. The procedure allows the representation of a given molecule initially described in terms ofnth order density functions as a point in a finite dimensional Euclidean space: apoint-molecule. Further manipulation of the obtained information permits the representation of a molecular set as a cloud of points: amolecular point cloud, in a variety of graphical manners. A previous experience in the field is compared with this new approach.A contribution of the Grup de Química Quàntica del Institut d'Estudis Catalans.     

Software development to fermentation gas analysis using mass spectrometry

Summary Fermentation applications of mass spectrometer (Spectramass PC2000) hampered by interface and software difficulties have been successfully solved. A multiplexed exhaust gas analysis, data acquisition and estimation system was designed and implemented. An specific software was developed in C+ + language programming. This system was tested for lipase production by Candida rugosa in batch fermentation.     

Plant-microbe interactions and the new biotechnological methods of plant disease control

Plants constitute an excellent ecosystem for microorganisms. The environmental conditions offered differ considerably between the highly variable aerial plant part and the more stable root system. Microbes interact with plant tissues and cells with different degrees of dependence. The most interesting from the microbial ecology point of view, however, are specific interactions developed by plant-beneficial (either non-symbiotic or symbiotic) and pathogenic microorganisms. Plants, like humans and other animals, also become sick, but they have evolved a sophisticated defense response against microbes, based on a combination of constitutive and inducible responses which can be localized or spread throughout plant organs and tissues. The response is mediated by several messenger molecules that activate pathogen-responsive genes coding for enzymes or antimicrobial compounds, and produces less sophisticated and specific compounds than immunoglobulins in animals. However, the response specifically detects intracellularly a type of protein of the pathogen based on a gene-for-gene interaction recognition system, triggering a biochemical attack and programmed cell death. Several implications for the management of plant diseases are derived from knowledge of the basis of the specificity of plant-bacteria interactions. New biotechnological products are currently being developed based on stimulation of the plant defense response, and on the use of plant-beneficial bacteria for biological control of plant diseases (biopesticides) and for plant growth promotion (biofertilizers). Electronic Publication