Comparison of extraction methods for analysis of flavonoids in onions

Onions are known to contain high levels of flavonoids and a comparison of the efficiency, reproducibility and detection limits of various extraction methods has been made in order to develop fast and reliable analytical methods for analysis of flavonoids in onions. Conventional and classical methods are time- and solvent-consuming and the presence of light and oxygen during sample preparation facilitate degradation reactions. Thus, classical methods were compared with microwave (irradiation) extraction, ultrasonic liquid extraction and accelerated solvent extraction

Bioactive metabolites in crops, diets and human samples

The objective of the PhD-project is to characterize bioactive metabolites, such as polyphenols, in selected crops and investigate the influence of different organic farming systems on the ability of crops to synthesize bioactive compounds with health promoting effects. The study includes two organic and one conventional farming system and is part of the OrgTrace project (content, bioavailability and health effects of trace elements and bioactive components in organic agricultural systems), where harvest takes place in autumn 2007 and 2008

Nyt dyrkningssystem til effektiv ukrudtsbekæmpelse og optimeret dyrkning af efterafgrøder

Nye radrensere med stor præcision og kapacitet giver forbedrede muligheder for ukrudtsbekæmpelse i afgrøder sået på øget rækkeafstand. Dette kan anvendes, så både ukrudtsbekæmpelse og etablering af efterafgrøder forbedres

Kørselsafgifter -et studie af befolkningens forståelse, accept og holdning

Paperet tager udgangspunkt i et ønske om ændret transportadfærd og retfærdig prissætning af eksternaliterne ved transport gennem indførelsen af et strækningsbaseret kørselsafgiftssystem. I.f.m. 9.semesters studieprojekt i efteråret 1999 på Aalborg Universitet er der foretaget undersøgelser af befolkningen forståelse, accept og holdning til kørselsafgifter gennem fire fokusgruppeinterviews ud fra forskningsgruppen FORTRINs prototype af et kørselsafgiftssystem. Paperet fremdrager de væsentligste resultater af undersøgelsen samt en præsentation af anvendelsen af fokusgruppeinterview som metode –fordelene og ulemperne herved

Sokratiske samtaler i naturfagsundervisningen

Klasserumssamtaler i naturfagsundervisning følger ofte den triadiske dialogform med det resultat at få elever deltager og eventuelt kun med en overfladisk forståelse af begreberne. Denne artikel omhandler en undersøgelse af klasserumsdiskursen under opstarten af et geografiforløb i en 9.-klasse med afsæt i Martin Wagenscheins sokratiske samtaleprincip. Den efterfølgende analyse peger på at eleverne undervejs udviklede en mere undrende tilgang til de præsenterede fænomener og indgik mere i dialog med hinanden. Undersøgelsen efterlader derfor grundlag for yderligere afprøvning af Wagenscheins undervisningsprincip og hvilke effekter det kan have på elevernes begrebsforståelse og misforståelse. &nbsp

OrgTrace – No Difference in Levels of Bioactive Compounds found in Crops from Selected Organic and Conventional Cultivation Systems

The objective of the present study was to compare the content of selected bioactive compounds in organically and conventionally grown crops, and to evaluate if the ability of the crops to synthesize selected secondary metabolites was systematically affected by growth systems across different growth years as well as soil types. The results showed that contents of neither polyacetylenes and carotenoids in carrots, flavonoids in onions, nor phenolic acids in carrots and potatoes were significantly influenced by growth system. Thus it could not be concluded that the organically grown crops had higher contents of bioactive compounds than the conventionally grown. This indicates that giving preference to organic products because they contain more bioactive components is doubtfull. However, there are many other reasons for the consumer to choose organic food products, including: no pesticide residues in foods, animal welfare, and environmental protection

Rational Management of Iron-Deficiency Anaemia in Inflammatory Bowel Disease

Anaemia is the most frequent, though often neglected, comorbidity of inflammatory bowel disease (IBD). Here we want to briefly present (1) the burden of anaemia in IBD, (2) its pathophysiology, which mostly arises from bleeding-associated iron deficiency, followed by (3) diagnostic evaluation of anaemia, (4) a balanced overview of the different modes of iron replacement therapy, (5) evidence for their therapeutic efficacy and subsequently, (6) an updated recommendation for the practical management of anaemia in IBD. Following the introduction of various intravenous iron preparations over the last decade, questions persist about when to use these preparations as opposed to traditional and other novel oral iron therapeutic agents. At present, oral iron therapy is generally preferred for patients with quiescent IBD and mild iron-deficiency anaemia. However, in patients with flaring IBD that hampers intestinal iron absorption and in those with inadequate responses to or side effects with oral preparations, intravenous iron supplementation is the therapy of choice, although information on the efficacy of intravenous iron in patients with active IBD and anaemia is scare. Importantly, anaemia in IBD is often multifactorial and a careful diagnostic workup is mandatory for optimized treatment. Nevertheless, limited information is available on optimal therapeutic start and end points for treatment of anaemia. Of note, neither oral nor intravenous therapies seem to exacerbate the clinical course of IBD. However, additional prospective studies are still warranted to determine the optimal therapy in complex conditions such as IBD

Mapping the polysaccharide degradation potential of Aspergillus niger

<p>Abstract</p> <p>Background</p> <p>The degradation of plant materials by enzymes is an industry of increasing importance. For sustainable production of second generation biofuels and other products of industrial biotechnology, efficient degradation of non-edible plant polysaccharides such as hemicellulose is required. For each type of hemicellulose, a complex mixture of enzymes is required for complete conversion to fermentable monosaccharides. In plant-biomass degrading fungi, these enzymes are regulated and released by complex regulatory structures. In this study, we present a methodology for evaluating the potential of a given fungus for polysaccharide degradation.</p> <p>Results</p> <p>Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this with a list of 188 genes coding for carbohydrate-active enzymes from <it>Aspergillus niger</it>, thus forming an analysis framework, which can be queried. Combination of this information network with gene expression analysis on mono- and polysaccharide substrates has allowed elucidation of concerted gene expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan.</p> <p>Conclusions</p> <p>The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for expression analysis of carbohydrate-active enzymes. Applying this network-based approach, we provide the first genome-scale characterization of all genes coding for carbohydrate-active enzymes identified in <it>A. niger</it>.</p