| 641. |
- Shchukarev, Andrey, et al.
(författare)
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XPS study of living tree : Per Persson
- 2002
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Ingår i: Surface and Interface Analysis. - : Wiley. - 0142-2421 .- 1096-9918. ; 34:1, s. 284-8
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Tidskriftsartikel (refereegranskat)abstract
- X-ray photoelectron spectroscopy (XPS) was used to study the distribution of elements and main wood components (cellulose and lignin) within the wood and at the bark/wood interface of a living hybrid aspen stem. The hybrid aspen was grown upright in a greenhouse and then tilted at 45° to induce tension wood formation and upright bending of the stem. The wood between the pith and the bark on the upper side of the tilted stem was analysed. Changes in the middle lamella/S1 layer chemical composition, which corresponded to the transition from normal wood produced during upright stem growth to tension wood produced upon stem tilting, were observed. Such changes were related to the lower lignin and higher cellulose/hemicellulose contents in the tension wood. A non-uniform radial distribution of nitrogen (amino acids, proteins) within the stem was also noted. At the bark/wood interface the presence of inorganic elements (Ca, K and P) and a significant increase in nitrogen were found. The opposite wood side of the tree was enriched in lignin and fatty acids. It was shown that application of XPS imaging to a very rough surface of wood split allows the inhomogeneous lateral lignin distribution to be visualized. Copyright © 2002 John Wiley & Sons, Ltd.
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| 642. |
- Sheals, Julia, et al.
(författare)
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Adsorption of Glyphosate on Goethite: Molecular Characterization of Surface Complexes
- 2002
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Ingår i: Environmental Science & Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 36:14, s. 3090-5
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Tidskriftsartikel (refereegranskat)abstract
- As a component of herbicides, the fate of glyphosate (PMG) in the environment is of significant interest. The nature of PMG adsorption on mineral surfaces plays a significant role in the degradation of PMG. The adsorption of PMG on goethite (-FeOOH) has been studied as a function of pH and PMG concentration. Adsorption was investigated with batch experiments, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). The N 1s line in XPS spectra showed deprotonation of the amine group of PMG (NH2+) with increasing pH. IR analyses showed no evidence for the interaction of PMG's carboxylate group with the goethite surface, while the phosphonate group formed inner-sphere complexes. There is evidence for intramolecular hydrogen bonding between NH2+ and both the carboxylate and the phosphonate groups at low pH. Intramolecular hydrogen bonding is lost when the amine group is deprotonated, and the trend in intramolecular hydrogen bonding between NH2+ and phosphonate shows that PMG adsorbs via predominantly monodentate complexation. A minor quantity of bidentate complexes is thought to form both at near-neutral pH and when the surface concentration of PMG is low. While the phosphonate group of PMG binds directly, the carboxylate group remains relatively "free" from complexation with goethite, leaving it subject to degradation and/or complexation with metal ions present in the environment.
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| 643. |
- Shibre, T, et al.
(författare)
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An evaluation of two screening methods to identify cases with schizophrenia and affective disorders in a community survey in rural Ethiopia
- 2002
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Ingår i: International Journal of Social Psychiatry. - : Sage Publications. - 0020-7640 .- 1741-2854. ; 48:3, s. 200-208
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Tidskriftsartikel (refereegranskat)abstract
- Background: Detecting cases with psychiatric disorders in the general population is costly and it is not clear which is the method of choice for community surveys in low-income countries. Aim: To compare the performance of a standardized diagnostic layman interview instrument-the Composite International Diagnostic Interview (CIDI 2.1) versus the Key Informant method in identifying cases with schizophrenia and major affective disorders in a community survey. Method: Both screening methods were tested against an expert interview the Schedule for Clinical Assessment in Neuropsychiatry (SCAN 2.1) in a rural district in Ethiopia with 25,632 inhabitants. Result: CIDI identified 524 and key informants 192 individuals as probable cases who were invited for a further SCAN interview. Seventy-two individuals were identified by both methods. Of those identified as probable cases by either method, a total of 481 volunteered the SCAN interviews. The Key Informant method alone detected more cases of schizophrenia, 59 vs. 29 for CIDI, whereas CIDI alone detected more cases of affective disorders, 45 vs. 30. Key informants performed better in detecting chronic cases. Conclusion: For community surveys, which aim at identifying cases with major mental disorders in low-income countries like Ethiopia, the combined use of both CIDI and the Key Informant method is recommended.
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| 644. |
- Shibre, Teshome, et al.
(författare)
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Neurological soft signs (NSS) in 200 treatment-naïve cases with schizophrenia : a community-based study in a rural setting.
- 2002
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Ingår i: Nordic Journal of Psychiatry. - : Informa UK Limited. - 0803-9488 .- 1502-4725. ; 56:6, s. 425-31
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Tidskriftsartikel (refereegranskat)abstract
- Several studies have reported neurological soft signs (NSS) to be common in individuals with schizophrenia. The majority of these studies are based on clinical samples exposed to neuroleptic treatment. The present study reports on 200 treatment-naïve and community-identified cases of schizophrenia and 78 healthy individuals from the same area, evaluated using the Neurological Evaluation Scale (NES). The median NES score was 5.0 for cases of schizophrenia and 1.5 for healthy subjects. The impairment rate of NSS in cases with schizophrenia was 65.0% against 50.0% in healthy subjects, and the difference was statistically significant (chi2 = 5.30; df = 1; P < 0.021). NSS abnormality is as common in treatment-naïve cases as reported in many studies in those on neuroleptic medication. There was no significant relation between the NSS impairment and duration of illness, remission status, positive symptoms, negative symptoms and disorganized symptoms.
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| 645. |
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| 646. |
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| 647. |
- Sibeyn, J. F.
(författare)
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One-by-one cleaning for practical parallel list ranking
- 2002
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Ingår i: Algorithmica. ; 32:3, s. 345-363
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Tidskriftsartikel (refereegranskat)abstract
- It is hard to achieve good speed-ups for parallel list ranking on distributed-memory machines because the problem requires a substantial number of communication rounds, each incurring some start-up delay. For input sizes N that are very large in comparison with the number of processors P these start-up costs can be amortized to a certain extent. For modest NIP values, so far the best approach was the basic pointer-jumping approach. In this paper a novel algorithm, one-by-one cleaning, is presented. It has the unique property that the routing consists of O(P) rounds in which each processing unit (PU) sends a packet to only one other PU. Pointer jumping requires a logarithmic number of rounds in which each PU sends a packet to all other PUs. Because the constants are small, and the internal work performed is less than that of pointer jumping, one-by-one cleaning is about twice as fast, which is demonstrated by comparing the performance of implementations of both algorithms on the Intel Paragon.
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| 648. |
- Silfverdal, Sven-Arne, et al.
(författare)
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Long term enhancement of the IgG2 antibody response to Haemophilus influenzae type b by breast-feeding.
- 2002
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Ingår i: The Pediatric Infectious Disease Journal. - 0891-3668 .- 1532-0987. ; 21:9, s. 816-21
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Tidskriftsartikel (refereegranskat)abstract
- SUBJECTS: Sets of sera were obtained from 30 children <6 years of age with invasive type b (Hib) infection and their mothers. Duration and mode of breast-feeding were monitored. Titers of IgG1, IgG2, IgA and IgM antibodies against Hib capsular polysaccharide were determined in sera taken during the acute illness and during early and late convalescence. RESULTS: Children 18 months or older with longer durations of exclusive breast-feeding (13 weeks or more; mean, 19.3 weeks) had higher Hib antibody concentrations of the IgG1, IgG2, IgA and IgM isotypes than those with a shorter duration of exclusive breast-feeding (<13 weeks; mean, 5.4 weeks). The difference was greatest for the IgG2 isotype. In regression analyses the association between the duration of exclusive breast-feeding and the anti-Hib IgG2 concentration was significant when breast-feeding, type of Hib infection, maternal Hib antibody titer and age were used as explanatory factors. In the group of 14 children <18 months of age no significant differences were noted. DISCUSSION: This study indicates the presence of a long lasting enhancing effect of breast-feeding on the antibody response to Hib in children, in particular on IgG2 Hib antibody production. This may result from the content in the milk of IFN-gamma and IFN-gamma-producing cells and possibly other factors, which can support IgG2 antibody production.
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| 649. |
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| 650. |
- Sironen, Reijo, et al.
(författare)
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cDNA array reveals mechanosensitive genes in chondrocytic cells under hydrostatic pressure.
- 2002
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Ingår i: Biochimica et Biophysica Acta. - : Elsevier. - 0006-3002 .- 1878-2434. ; 1591:1-3, s. 45-54
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Tidskriftsartikel (refereegranskat)abstract
- Hydrostatic pressure (HP) has a profound effect on cartilage metabolism in normal and pathological conditions, especially in weight-bearing areas of the skeletal system. As an important component of overall load, HP has been shown to affect the synthetic capacity and well-being of chondrocytes, depending on the mode, duration and magnitude of pressure. In this study we examined the effect of continuous HP on the gene expression profile of a chondrocytic cell line (HCS-2/8) using a cDNA array containing 588 well-characterized human genes under tight transcriptional control. A total of 51 affected genes were identified, many of them not previously associated with mechanical stimuli. Among the significantly up-regulated genes were immediate-early genes, and genes involved in heat-shock response (hsp70, hsp40, hsp27), and in growth arrest (GADD45, GADD153, p21(Cip1/Waf1), tob). Markedly down-regulated genes included members of the Id family genes (dominant negative regulators of basic helix-loop-helix transcription factors), and cytoplasmic dynein light chain and apoptosis-related gene NIP3. These alterations in the expression profile induce a transient heat-shock gene response and activation of genes involved in growth arrest and cellular adaptation and/or differentiation.
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