Atmospheric Water Vapor Transport in NCEP–NCAR Reanalyses: Comparison with River Discharge in the Central United States

The authors extract the water transport produced by the National Centers for Environmental Prediction reanalysis for a 10-yr period, 1984–93, and compare its convergence into two river basins with an independent dataset, river discharge (streamflow). Analysis focuses on two basins in the United States, the Upper Mississippi and the Ohio–Tennessee Basins, where the relatively high density of routine upper-air observations might be expected to give the reanalysis its closest rendition of the actual water transport. Over periods of several years, water input by the atmosphere should match water output from these basins in streamflow. However, in both basins an imbalance between the two with biases with respect to streamflow approaching 40% is found. The accuracy attributed to river discharge measurements averaged over several years and the apparent lack of significant multiyear storage in the basins lead us to conclude that the bias is largely an inaccuracy in the atmospheric transport. Temporal variability of atmospheric input and streamflow output shows somewhat better correspondence, with statistically significant correlations occurring for both basins on interannual and several-day timescales. The overall behavior suggests that the temporal variability of water transport depicted by the reanalysis can be used to gain insight into the actual variability of atmospheric transport, at least for well-observed regions such as the United States

SC IE N T I A R U M PO L O N O R U M ACTA Corresponding author -Adres do korespondencji: ORGANIC FISH PRODUCTION AND THE STANDARDS

Abstract. Fish that are produced under natural conditions in accordance with the principles of organic agriculture without any use of preservative additives and without any genetic modifications, that are fed feed produced from natural raw materials, that are certified by a qualified institution are defined as "organic fish". Organic fish production is a production model that emphasizes human health without using pesticides, chemical and genetically modified products, as well as ensuring animal welfare by decreasing the stocking density. This alternative model is used in many developed and developing countries in the world and the demand for this product has been the cause of increase in production amount and species variety in the market, although the model comprises 0.01% of the world aquaculture production. However, organic aquaculture production has not been developed as rapidly as organic agriculture. One of the most important reasons of this is the absence of international standards issued for organic aquaculture production. In this paper, the production principles of a number of authorized institutions certifying organic aquaculture are comparatively discussed

Comparative determination of ascorbic acid in bass (morone lebrax) liver by HPLC and DNPH methods

PubMed ID: 7584161A reverse-phase high pressure liquid chromatographic technique (RP-HPLC) was developed for the analysis of ascorbic acid in bass liver. Ascorbic acid was extracted from bass liver and simultaneously assayed by RP-HPLC. The results were compared to the Dinitrophenylhydrazine (DNPH) method now in use. Recovery studies showed about 97% by the HPLC method compared to about 96% by the DNPH method. There was no statistically significant difference found in the values obtained from the two methods. The HPLC method described here is considered the preferred method both in terms of a shorter analysis time and greater sensitivity. © 1995 Informa UK Ltd All rights reserved: reproduction in whole or part not permitted

Handbook of food analysis instruments

Explore the Pros and Cons of Food Analysis Instruments: The identification, speciation, and determination of components, additives, and contaminants in raw materials and products will always be a critical task in food processing and manufacturing. With contributions from leading scientists, many of whom actually developed or refined each technique or instrument, the Handbook of Food Analysis Instruments discusses how to apply proper methods and use increasingly sophisticated instruments. Examine Benefits, Drawbacks, and Appropriate Use: In a format that facilitates comparison of techniques, the book presents each technique in a uniform and easily accessible style. It begins with information relevant to all techniques, including calibration, standard addition, internal standards, selectivity, accuracy, precision, detection limit, quantification limit, range, robustness, speed, and convenience. Each subsequent chapter focuses on a specific type of instrument and includes a description of the information the technique can provide, a simple explanation of how it works, and examples of its application. The chapters also provide practical information such as names of instrument vendors, relative costs of instruments and materials, training and education of personnel, and references for more detailed information. Increasingly Sophisticated Instruments Solve Analysis Problems: While there are any number of books that explain the principles of food analysis, describe how to conduct food analysis, and discuss test results, there are few that focus on understanding the actual instruments used in the analysis. Prepared by a team of food scientists, chemists, and biochemists, this handbook provides a valuable reference on the instruments of newly developed and practiced methods of analysis of food components and additives. Using the information in this book, readers can analyze each technique's potential benefits and limitations and apply them to solve specific problems. © 2009 by Taylor & Francis Group, LLC. All Rights Reserved