1,554 research outputs found
A possible role for vitamin C in age-related cataract
No full textWhile many experimental studies have shown a protective effect of vitamin C in age-related cataract, other studies have revealed contrasting roles for this nutrient. Oxidative damage in the lens can be prevented by vitamin C. However, a pro-oxidant effect of vitamin C through H2O2 generation has been suggested. Vitamin C has also been shown to play a role in protein glycation, which is observed in cataract formation. A protective effect of dietary energy restriction appears to be inversely related to plasma vitamin C levels in rodents. Moreover, conclusions from human epidemiological and intervention studies are not uniform. The available evidence suggests that maintenance of sufficient plasma vitamin C is needed to prevent oxidative damage in the lens. More research will be needed in order to confirm the relative importance of of the different roles of vitamin C in the eye lens
Stoombemaling in Nederland 1770-1870
No full textIn 1984 bestond de Stichting De Cruquius vijftig jaar. Dit werd gevierd met een symposium; de deelnemers daaraan ontvingen het boekje De ontwikkeling van het wateropvoerwerktuig in Nederland 1770-1870. Dit was van de hand van een van de sprekers - Ir. K. van der Pols, oud-voorzitter van de Stichting en erelid van haar Raad van Advies. Het werkje, een verkorte en aangevulde bewerking van een boek uit 1885, was uitgegeven onder auspiciën van het Bataafsch Genootschap der Proefondervindelijke Wijsbegeerte te Rotterdam. Dat Genootschap speelde in de achttiende eeuw een cruciale rol bij de ontwikkeling van stoombemaling in Nederland. Van der Pols was 29 jaar lid van het College van Directeuren ervan en hij vervulde vijf termijnen als voorzitter. De Stichting is het Bataafsch Genootschap erkentelijk voor de steun aan deze vernieuwde uitgave. Zij is voorts Ir. J.A. Verbruggen, waardig opvolger van Van der Pols als stoomhistoricus, dankbaar voor de verzorging - bewerking, vertaling en opmaak - van het boekje, naast zijn werkzaamheden aan het weer in beweging stellen van de grootste stoommachine ter wereld. De Stichting is de erven Van der Pols dank verschuldigd voor hun welwillende medewerking en dankt de uitgever en de drukker voor de goede verzorging
Formation and evolution of carbon-enhanced metal-poor stars
No full textContains fulltext :
132152.pdf (Publisher’s version ) (Open Access)Radboud Universiteit Nijmegen, 10 december 2014Promotor : Verbunt, F.W.M. Co-promotor : Pols, O.R.221 p
Acute suppression of Ezh2 induces apoptosis in pOLs.
No full text<p>(<b>A</b>, <b>B</b>) Phase contrast images show that pOLs retract their projections when treated with Ezh2-shRNA. (<b>C</b>, <b>D</b>) Immunostaining for apoptosis marker, cleaved caspase 3 (green) shows increase in cell death in pOLs cultures treated with Ezh2-shRNA compared to control cultures (nc-shRNA). (<b>E</b>, <b>F</b>) Co-immunostaining using anti-cleaved caspase 3 and anti-RIP (an oligodendrocyte maker) shows restriction of cell extensions and increased cell death, in cultures treated with Ezh2-shRNA. (<b>G</b>) Western blot of protein samples prepared after 24 hours of transfection shows a decrease in Ezh2 and a strong increase in cleaved caspase 3 bands in pOLs treated with Ezh2-shRNA, compared to the cultures treated with nc-shRNA (control). PCNA (a proliferation marker) expression remained about the same in both conditions<b>.</b> (<b>H</b>) Quantification of apoptotic (cleaved caspase 3-positive) and differentiating (RIP-positive) cells in Ezh2-shRNA treated and control (nc-shRNA) pOLs. Bar graphs represent mean of three independent experiments ± S.D. (Calibration bar in (<b>A</b>) represents 100 micrometers, which is valid for all the photomicrographs (<b>A</b>–<b>F</b>); ** in (<b>H</b>) represents p<0.01).</p
De ontwikkeling van het wateropvoerwerktuig in Nederland 1770-1870
No full textIn 'De ontwikkeling van het wateropvoerwerktuig in Nederland, 1770- 1870' beschrijft de auteur, ir. K. van der Pols, de ontwikkeling van het door stoom gedreven bemalingswerktuig in Nederland vanaf de veelal omstreden experimentele fase in 1770 tot aan de meer algemeen aanvaarde techniek in 1870. Daarbij besteedt hij aandacht aan zowel de toegepaste constructies, als aan de personen die bij de uitvoering waren betrokken. Voorts evalueert hij de resultaten gezien vanuit de ten tijde van de bouw geldende maatstaven en gezien vanuit de huidige opvattingen. In dit boek zijn opgenomen de beschouwingen uit Huet's 'Stoombemaling van Polders en Boezems' (Den Haag, 1885), aangevuld met essentiële gedeelten van het toen bekende bronmateriaal en met nieuwe gegevens. Voor belangstellenden in de geschiedenis der techniek en de technische archeologie zal deze uitgave in een behoefte voorzien.Delft University of Technolog
Relative validity of food intake estimates using a food frequency questionnaire is associated with sex, age, and other personal characteristics
No full textWe invostigated the validity of food intake estimates obtained by a self-administered FFQ relative to weighed food records (WFR) and the extent to which demographic, anthropometric, and social characteristics explain differences between these methods. A community-based sample of 96 Australian adults completed a FFQ and 12 d of WFR over 12 mo. The FFQ was adapted to the Australian setting from the questionnaire used in the US Nurses' Health Study. Spearman rank correlation coefficients ranged from 0.08 for other vegetables to 0.88 for tea. Exact agreement by quartiles of intake ranged from 27% (eggs) to 63% (tea). Differences between FFQ and WFR regressed on personal characteristics were significantly associated with at least 1 characteristic for 20 of the 37 foods. Sex was significantly associated with differences for 17 food groups, including 5 specific vegetable groups and 2 total fruit and vegetable groups. Use of dietary supplements and the presence of a medical condition were associated with differences for 5 foods; age, school leaving age, and occupation were associated with differences for 1-3 foods. BMI was rot associated with differences for any foods. Regression models explained from 3% (wholemeal bread) to 37% (for all cereals and products) of variation in differences between methods. We conclude that the relative validity of intake estimates obtained by FFQ is different for men and women for a large number of foods. These results highlight the need for appropriate adjustment of diet-disease relations for factors affecting the validity of food intake estimates
Target genes of Ezh2 in NSCs and pOLs.
No full text<p>(<b>A</b>–<b>B”</b>) Association of input genomic regions with the transcription start site (TSS) of all the genes putatively regulated by the genomic regions in NSCs (<b>A</b>–<b>A”</b>) and pOLs (<b>B</b>–<b>B”</b>). (<b>A</b>, <b>B</b>) “Number of associated genes per region" graphs show how many genes in each genomic region is assigned as putatively regulating based on the association rule used. (Details of association rule see online: <a href="http://great.stanford.edu/public/html/help/index.php?title=Association_Rules" target="_blank">http://great.stanford.edu/public/html/help/index.php?title=Association_Rules</a>). (<b>A’</b>, <b>B’</b>) Graphs show the distance between input regions and their putatively regulated genes (i.e. binned by orientation and distance to TSS). The distances are divided into four separate bins: 0 to 5 kb, 5 kb to 50 kb, 50 kb to 500 kb, and >500 kb. All associations precisely at 0 (i.e. on the TSS) are split evenly between the [−5 kb, 0] and [0,5 kb] bins. (<b>A”</b>, <b>B”</b>) Binned by absolute distance to TSS (only the distance to TSS is considered, not the orientation). Functional gene ontology (GO) analysis of Ezh2 target genes (DAVID online tool) in NSCs (<b>C</b>) and pOLs (<b>D</b>). The bar graphs represent the percentage of DAVID genes (since DAVID converts user input gene IDs to corresponding DAVID gene IDs) in the list associated with particular annotation term. The corresponding line graphs represent –log10 transformation of the modified Fisher Exact P-value. Fisher Exact is adopted to measure the gene-enrichment in annotation terms. The smaller the P-value, the more enriched a GO term is for genes of the given assay. (<b>E</b>) Comparison of canonical signaling pathways enriched in Ezh2 target genes in NSCs and pOLs.</p
Supporting forensic investigators on exploring web forums through Interactive Topic Modeling
No full textForums on the Web have become a highly popular platform for malicious activities as recent technologies allow to preserve anonymity. Forensic investigators are more and more interested to use these forums on the so-called Dark Web as their source of intelligence. Exploring the forums one by one is too time-consuming and it requires much effort of the investigator to create an overview. Topic Modeling (TM) has shown to be able to give insights on discussions on forums, this way improving the exploration of this unknown data, as an alternative to a traditional search engine. Interactive Topic Modeling (ITM) moreover has been introduced as a technique to incorporate the domain knowledge of the user into the generated topic model. As the investigators have much domain knowledge, incorporating their knowledge into the topic models should increase the quality of the model and align it the goal of the investigator. In lab studies in related work, ITM has shown to outscore both TM and traditional search. In this thesis, we evaluate the effectiveness, efficiency and preference of using ITM in a more realistic setup with stakeholders (forensic investigators) in a domain of their expertise (the Dark Web) in a user study setup. For this, based on stakeholder interviews and earlier research, we designed and built an ITM framework to explore forums on the Dark Web. We found that TM was more effective than ITM for forensic investigators to complete their tasks. Furthermore, traditional search was found most efficient and preferred. It was observed that participants incorrectly interacted with the topic model. Additionally, we found that the difficulty of a task influenced the use of ITM versus search. Users were found to fall back on using traditional search to complete their task more often for tasks with a low or high difficulty. We state that as ITM is introduced as a promising technique in lab studies; more effort is needed in explaining its use to the end user.Electrical Engineering, Mathematics and Computer ScienceSoftware TechnologyWeb Information System
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