707 research outputs found
Untersuchungen ueber den Pflanzenparasiten Verticillium albo - atrum Reinke et Berth.
Among 70 Verticillium strains isolated from different hosts throughout the Netherlands, only 2 had the bundled dark hyphae described by Reinke and Berthold (1879) as characteristic of V.albo-atrum Reinke & Berth. This species was morphologically the same as V. dahliae Klebahn. The name V.albo-atrum had priority.Strains with loose dark hyphae (d.m. type) were less resistant to warmth (35øC) than those with microsclerotia (mscl. type). On artificial media all strains produced toxins, specific for each strain but not correlated with type or pathogenicity. The fungus spreads through the plant's vessels as spores or mycelium. The physiological range confirmed that there was no clear distinction between the two species but demonstrated a difference between mycelial and microsclerotial types. Host range was not limited (contrast Nelson, 1950; Isaac, 1957). Culture on tomato changed the virulence.Both types could spread in sterile soil between roots of antirrhinums only as hyphae. After 4 years in the soil only the mscl. type was slightly infective.Microsclerotia were assumed to be merely storage organs because they did not germinate, even with root secretions.After an infection resistant crops should be planted and possible carrier weeds eradicated. Use of resistant varieties was difficult because of differences in pathogenicity of Verticillium strains but chemical control was inadequate.<p/
How design can improve company performance
Emphasising design and including designers in product
development teams contributes to new product success.
Likewise, involving designers in developing websites and
corporate visual identity helps to improve firm image. When
taken together this can contribute to improved company
performance. These are the main findings of research
conducted in a survey of nearly 400 managers in Dutch firms
from both manufacturing and service sectors
Cloning and functional characterization of a fructan 1-exohydrolase (1-FEH) in edible burdock (Arctium lappa L.)
<p>Abstract</p> <p>Background</p> <p>We have previously reported on the variation of total fructooligosaccharides (FOS), total inulooligosaccharides (IOS) and inulin in the roots of burdock stored at different temperatures. During storage at 0°C, an increase of FOS as a result of the hydrolysis of inulin was observed. Moreover, we suggested that an increase of IOS would likely be due to the synthesis of the IOS by fructosyltransfer from 1-kestose to accumulated fructose and elongated fructose oligomers which can act as acceptors for fructan:fructan 1-fructosyltransferase (1-FFT). However, enzymes such as inulinase or fructan 1-exohydorolase (1-FEH) involved in inulin degradation in burdock roots are still not known. Here, we report the isolation and functional analysis of a gene encoding burdock 1-FEH.</p> <p>Results</p> <p>A cDNA, named <it>aleh1</it>, was obtained by the RACE method following PCR with degenerate primers designed based on amino-acid sequences of FEHs from other plants. The <it>aleh1 </it>encoded a polypeptide of 581 amino acids. The relative molecular mass and isoelectric point (<it>pI</it>) of the deduced polypeptide were calculated to be 65,666 and 4.86. A recombinant protein of <it>aleh1 </it>was produced in <it>Pichia pastoris</it>, and was purified by ion exchange chromatography with DEAE-Sepharose CL-6B, hydrophobic chromatography with Toyopearl HW55S and gel filtration chromatography with Toyopearl HW55S. Purified recombinant protein showed hydrolyzing activity against β-2, 1 type fructans such as 1-kestose, nystose, fructosylnystose and inulin. On the other hand, sucrose, neokestose, 6-kestose and high DP levan were poor substrates.</p> <p>The purified recombinant protein released fructose from sugars extracted from burdock roots. These results indicated that <it>aleh1 </it>encoded 1-FEH.</p
Optofluidic lens with tunable focal length and asphericity
Adaptive micro-lenses enable the design of very compact optical systems with tunable imaging properties. Conventional adaptive micro-lenses suffer from substantial spherical aberration that compromises the optical performance of the system. Here, we introduce a novel concept of liquid micro-lenses with superior imaging performance that allows for simultaneous and independent tuning of both focal length and asphericity. This is achieved by varying both hydrostatic pressures and electric fields to control the shape of the refracting interface between an electrically conductive lens fluid and a non-conductive ambient fluid. Continuous variation from spherical interfaces at zero electric field to hyperbolic ones with variable ellipticity for finite fields gives access to lenses with positive, zero, and negative spherical aberration (while the focal length can be tuned via the hydrostatic pressure)
Cost effectiveness of pneumococcal vaccination among Dutch infants: economic analysis of the seven valent pneumococcal conjugated vaccine and forecast for the 10 valent and 13 valent vaccines
Psychological outcomes of a Cognitive Behavioral Therapy for youth with Inflammatory Bowel Disease:Results of the HAPPY-IBD Randomized Controlled Trial at 6- and 12-month follow-up
Psychological Outcomes of a Cognitive Behavioral Therapy for Youth with Inflammatory Bowel Disease: Results of the HAPPY-IBD Randomized Controlled Trial at 6-and 12-Month Follow-Up
Youth with infammatory bowel disease (IBD) often experience psychological difculties, such as anxiety and depression.
This randomized controlled study tested whether a 3-month disease-specifc cognitive behavioral therapy (CBT) in addition to
standard medical care versus standard medical care only was efective in improving these youth’s psychological outcomes. As
this study was aimed at prevention, we included 70 youth (10–25 years) with IBD and symptoms of subclinical anxiety and/
or depression, and measured psychological outcomes at 6- and 12-month follow-up. In general, participants in both groups
showed improvements in anxiety, depression, health-related quality of life, social functioning, coping, and illness perceptions,
sustained until 12 months follow-up. Overall, we found no diferences between those receiving additional CBT and those
receiving standard medical care only. We assume that this can be explained by the perceived low burden (both somatically
and psychologically) or heightened awareness of psychological difculties and IBD
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