1,721,012 research outputs found
Heavy metals in sewage sludge and their impact on soil microorganisms. Agro-Food Industry Hi-Tech, March/April, 38-42, 1994
No full textUmbraculumin-B, An Unusual 3-hydroxybutyric Acid Ester From the Opisthobranch Mollusk Umbraculum mediterraneum
No full textThe structure and stcreochemistry of Umbraculumin-B, a metabolite isolated from the skin
extracts of the opisthobranch mollusc Umbraculum mediterraneum, have been established by
spectroscopic and chemical methods
Post-fire soil microbial biomass and nutrient content of a pine forest soil from a dunal Mediterranean environment
No full textA chronosequence of forest fires (from 1981 to 1992) in a homogeneous Mediterranean pine forest ecosystem was investigated. The effect of fire on soil microbial biomass was evaluated in the 0–5 cm soil layer utilizing the substrate induced respiration (SIR) method (Anderson and Domsch, 1978) and the fumigation extraction (FE) method (Sparling and West, 1988). The C, N and P contents of soil surface layer were greater 1 y after a fire and declined in soils as time since the last fire increased. After 11 y, the soil nutrient content and the size of the microbial biomass were still lower than the neighbouring unburned site suggesting that forest fires have a long-term effect on soil microbiological properties
Soil solarization. Effects on some microbiological and productive parameters [Lycopersicon esculentum Mill.-Basilicata]
No full textSoil solarization, using sun energy, is an agronomic pratice useful to reduce soil pathogen populations. Light plastic films have been contributing to improve soil solarization especially in open and in greenhouse vegetable crop cultivation. This kind of cover raises soil temperature up to 20 deg C in its first layers. Because of this effect and its lower costs, linked with ecological motivations, soil solarization is getting very common in vegetable crop field in Southern Italy. Soil solarization pratice, as before said, affects the soil microbial biomass content as direct heat influence. Very few studies have been carried out till now on this topic and on how the heat works in the soil reducing the microbial biomass content and affecting the bio-geo-chemistry cycle. In this paper, as a continual work, the soil solarization effects on some microbiological parameters and some enzyme activities, together with yield influences on fresh tomato berries, are reporte
Assay of Riboflavin in Sample Wines by Capillary Zone Electrophoresis and Laser-Induced Fluorescence Detection
No full textTo routinely assay the concentration of riboflavin (RF) in wines, a rapid and sensitive method was developed and evaluated. The method is based on a simple sample preparation, capillary zone electrophoretic separation and laser-induced fluorescence detection (CZE-LIF). Sample preparation required only dilution and filtration. Under optimized conditions, the limit of detection of riboflavin was 0.5 íg/L, using a hydrodynamic sample introduction of 10 s at 54 mbar. The method was fully validated: the recovery of RF in wines was >95%. The concentrations of RF within the three sample types of Italian wines investigated here ranged from 69 to 151 íg/L with a mean value ((SD) of 112 ( 25 íg/L, from 74 to 193 íg/L with a mean value of 115 ( 45 íg/L, and from 156 to 292 íg/L with a mean value of 226 ( 40 íg/L, for white, rose ́ , and red wines, respectively. Such an accurate and highly sensitive CZE-LIF method represents a powerful improvement over previous methods in terms of sensitivity, simplicity, and efficiency. It is well suited to satisfy the demands for accurate and sensitive detection with minimal sample preparation and cleanup
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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