bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytokine production by dendritic cells genetically engineered to express IL‐4: induction of Th2 responses and differential regulation of IL‐12 and IL‐23 synthesis
Authors: Morita Yoshitaka , Gupta Raj , Seidl Kelly M. , McDonagh Kevin T. , Fox David A.
Published: February 2005

Dendritic cells (DCs) retrovirally transduced with IL‐4 have recently been shown to inhibit murine collagen‐induced arthritis and associated Th1 immune responses in vivo, but the mechanisms that underly these effects are not yet understood. In this report we demonstrate that IL‐4‐transduced DCs loaded with antigen led to lower T cell production of IFN‐γ, increased production of IL‐4, and an attenuated, delayed type hypersensitivity response. We hypothesized that the ability of such DCs to regulate the Th1 immune response in vivo depends in part on their capacity to produce IL‐12 and IL‐23. Quantitative mRNA analysis revealed that IL‐4‐transduced DCs stimulated with CD40 ligand expressed higher levels of IL‐12p35 mRNA, but lower levels of mRNA for IL‐23p19 and the common subunit p40 found in both IL‐12 and IL‐23, compared with control DCs. These results, which indicate that expression of the IL‐12 and IL‐23 subunits is differentially regulated in IL‐4‐transduced DCs, were confirmed by ELISA of the IL‐12 and IL‐23 heterodimers. Thus, therapeutic suppression of Th1 ‐mediated autoimmunity (as recently shown in murine collagen‐induced arthritis) and induction of Th2 responses in vivo by IL‐4‐transduced DCs occurs despite their potential to produce increased levels of IL‐12, but could reflect, in part, decreased production of IL‐23. Copyright © 2005 John Wiley & Sons, Ltd.
Biocompatible polymer enhances the in vitro and in vivo transfection efficiency of HVJ envelope vector
Authors: Mima Hidetoshi , Tomoshige Ryuji , Kanamori Toshihide , Tabata Yasuhiko , Yamamoto Seiji , Ito Susumu , Tamai Katsuto , Kaneda Yasufumi
Published: February 2005

Background

Vector development is critical for the advancement of human gene therapy. However, the use of viral vectors raises many safety concerns and most non‐viral methods are less efficient for gene transfer. One of the breakthroughs in vector technology is the combination of the vector with various polymers.

Methods

HVJ (hemagglutinating virus of Japan) envelope vector (HVJ‐E) has been developed as a versatile gene transfer vector. In this study, we combined HVJ‐E with cationized gelatin to make it a more powerful tool and assessed its transfection efficiency in vitro and in vivo. In addition, we investigated the mechanism of the gene transfer by means of the inhibition of fusion or endocytosis.

Results

The combination of both protamine sulfate and cationized gelatin with HVJ‐E, referred to as PS‐CG‐HVJ‐E, further enhanced the in vitro transfection efficiency. In CT26 cells, the luciferase gene expression of PS‐CG‐HVJ‐E was approximately 10 times higher than that of the combination of protamine sulfate with HVJ‐E or the combination of cationized gelatin with HVJ‐E, referred to as PS‐HVJ‐E or CG‐HVJ‐E, respectively. Furthermore, the luciferase gene expression in liver mediated by intravenous administration of CG‐HVJ‐E was much higher than the luciferase gene expression mediated by PS‐HVJ‐E or PS‐CG‐HVJ‐E and approximately 100 times higher than that mediated by HVJ‐E alone.

Conclusions

Cationized gelatin‐conjugated HVJ‐E enhanced gene transfection efficiency both in vitro and in vivo. These results suggest that low molecular weight cationized gelatin may be appropriate for complex formation with various envelope viruses, such as retrovirus, herpes virus and HIV. Copyright © 2005 John Wiley & Sons, Ltd.
Targeted biomarker detection via whole protein ion trap tandem mass spectrometry: thymosin β4 in a human lung cancer cell line
Authors: Yan Fang , He Min , Hogan Jason M. , Rossie Sandra S. , McLuckey Scott A.
Published: February 2005

N‐Terminally acetylated thymosin β4, a species implicated for use as a cancer biomarker, was identified in a human lung cancer cell line using ion trap tandem mass spectrometry at the whole protein level. Ion–ion proton transfer reactions were used for parent ion concentration/manipulation and to simplify interpretation of product ion spectra. Dissociation data for the +6 to +3 charge states are reported. As is usually the case, structural information available from the ion trap collisional activation of the protein is sensitive to parent ion charge state. Each parent ion charge state selected, however, provided sufficient information to make a confident identification. Furthermore, each charge state provided relatively rich fragmentation. Therefore, any of the charge states can be used to detect with high specificity thymosin β4 in a complex protein mixture. There are advantages associated with the rapid detection of protein biomarkers at the whole protein level, as opposed to the peptide level following protein digestion, particularly for relatively small protein and polypeptide biomarkers. Having identified and characterized the protein, product ion spectra obtained directly, without recourse to ion–ion proton transfer reactions, can be used for library matching. However, ion–ion proton transfer reactions for parent ion concentration and charge state purification are advantageous in addressing relatively complex mixtures. Copyright © 2005 John Wiley & Sons, Ltd.
Development and validation of a liquid chromatographic/electrospray ionization mass spectrometric method for the quantitation of prazepam and its main metabolites in human plasma
Authors: Valavani Paraskevi , Atta‐Politou Julia , Panderi Irene
Published: February 2005

A method was developed and fully validated for the quantitation of prazepam and its major metabolites, oxazepam and nordiazepam, in human plasma. Sample pretreatment was achieved by solid‐phase extraction using Oasis HLB cartridges. The extracts were analysed by high‐performance liquid chromatography (HPLC) coupled with single‐quadrupole mass spectrometry (MS) with an electrospray ionization interface. The MS system was operated in the selected ion monitoring mode. HPLC was performed isocratically on a reversed‐phase XTerra MS C18 analytical column (150 × 3.0 mm i.d., particle size 5 µm). Diazepam was used as the internal standard for quantitation. The assay was linear over a concentration range of 5.0–1000 ng ml−1 for all compounds analyzed. The limit of quantitation was 5 ng ml−1 for all compounds. Quality control samples (5, 10, 300 and 1000 ng ml−1) in five replicates from three different runs of analysis demonstrated an intra‐assay precision (CV) of ≤9.1%, an inter‐assay precision of ≤6.0% and an overall accuracy (relative error) of <4.6%. The method can be used to quantify prazepam and its metabolites in human plasma covering a variety of pharmacokinetic or bioequivalence studies. Copyright © 2005 John Wiley & Sons, Ltd.
Comparative study of organic dyes with time‐of‐flight static secondary ion mass spectrometry and related techniques
Authors: Adriaensen L. , Vangaever F. , Lenaerts J. , Gijbels R.
Published: February 2005

A series of cationic, zwitterionic and anionic fluorinated carbocyanine dyes, spin‐coated on Si substrates, were measured with time‐of‐flight static secondary ion mass spectrometry (TOF‐S‐SIMS) under Ga+ primary ion bombardment. Detailed fragmentation patterns were developed for all dyes measured. In the positive mode, the resulting spectra showed very intense signals for the precursor ions of the cationic dyes, whereas the protonated signals of the anionic dyes were hardly detected. Differences of three orders of magnitude were repeatedly observed for the secondary ion signal intensities of cationic and anionic dyes, respectively. All measured dyes yielded mass spectra containing several characteristic fragment ions. Although the secondary ion yields were still higher for the cationic than the anionic dye fragments, the difference was reduced to a factor of ≤10. This result and the fact that M+, [M + H]+ or [M + 2H]+ are even‐electron species make it very likely that the recorded fragments were not formed directly out of the (protonated) parent ions M+, [M + H]+ or [M + 2H]+. In the negative mode, none of the recorded spectra contained molecular information. Only signals originating from some characteristic elements of the molecules (F, Cl), the anionic counter ion signal and some low‐mass organic ions were detected. A comparative study was made between TOF‐S‐SIMS, using Ga+ primary ions, and other mass spectrometric techniques, namely fast atom bombardment (FAB), electrospray ionization (ESI) and matrix‐assisted laser desorption/ionization (MALDI). The measurements showed that MALDI, ESI and FAB all give rise to spectra containing molecular ion signals. ESI and FAB produced M+ and [M + H]+ signals, originating from the cationic and zwitterionic dyes, in the positive mode and M− and [M − H]− signals of the anionic and zwitterionic dyes in the negative mode. With MALDI, molecular ion signals were measured in both modes for all the dyes. Structural fragment ions were detected for FAB, ESI and MALDI in both the positive and negative modes. Compared with the other techniques, TOF‐S‐SIMS induced a higher degree of fragmentation. Copyright © 2005 John Wiley & Sons, Ltd.
Plant‐growth‐promoting rhizobacteria isolated from a Calcisol in a semi‐arid region of Uzbekistan: biochemical characterization and effectiveness
Authors: Egamberdiyeva Dilfuza
Published: February 2005

Bacteria were isolated from the rhizosphere of cotton, wheat, alfalfa, and tomato grown in field locations within a semi‐arid region of Uzbekistan. Strains were identified as Pseudomonas denitrificans, P. rathonis, Bacillus laevolacticus, Bacillus amyloliquefaciens, and Arthrobacter simplex. The isolated strains produced different enzymes, phytohormone auxin and were antagonists against specific plant‐pathogenic fungi. Most of the strains are tolerant with respect to salt and temperature. All of the bacterial strains isolated in this study have been found to increase plant growth of wheat and maize in pot experiments.
Effects of nitrate‐, ammonium‐, and organic‐nitrogen‐based fertilizers on growth and yield of tomatoes
Authors: Heeb Anuschka , Lundegårdh Bengt , Ericsson Tom , Savage Geoffrey P.
Published: February 2005

Mineral and organic fertilizers contain different forms and amounts of nitrogen (N), which can affect yield and product quality. The aim of this study was to determine appropriate amounts of N applied as nitrate (NO$ _3^- $), ammonium (NH$ _4^+ $), and organic N (a mixture based on chicken manure) for optimal growth and quality of tomatoes. A pot experiment with sand as substrate was established in a greenhouse with six‐week‐old tomato plants (Lycopersicon esculentumMill. cv. “Armada”). Nitrogen was applied in nutrient solutions at different NO$ _3^- $: NH$ _4^+ $ratios combined with different chloride levels (NO$ _3^- $‐dominated, NO$ _3^- $= NH$ _4^+ $at low Cl–, NO$ _3^- $= NH$ _4^+ $at high Cl–, and NH$ _4^+ $‐dominated, respectively) or as organic N at four N‐application rates (250, 500, 750, 1000 mg N plant–1week–1). No significant differences in shoot biomass and yields of red tomatoes were observed between NO$ _3^- $‐ or NH$ _4^+ $‐fed plants. Nitrogen rates above 750 mg N plant–1week–1did not significantly increase marketable fruit yield, but enhanced shoot‐biomass production. The NH$ _4^+ $‐N‐dominated treatments (which also had high Cl–concentrations) showed increasing incidence of blossom‐end‐rot (BER)‐infected fruits. In the organic‐N treatments, shoot‐biomass production and yields were lower than in the inorganic‐N treatments, but fruit quality was good with few BER‐infected fruits. The results show that with a total N supply below 750 mg N plant–1week–1, NH$ _4^+ $can be used as equivalent N source to NO$ _3^- $, resulting in equivalent yields of marketable fruit under the conditions in this experiment.
Root morphology of Thlaspi goesingense Hálácsy grown on a serpentine soil
Authors: Himmelbauer Margarita L. , Puschenreiter Markus , Schnepf Andrea , Loiskandl Willibald , Wenzel Walter W.
Published: February 2005

The contribution of root morphology to enhanced uptake of heavy metals by hyperaccumulating plants is not well understood. The objective of this study was to describe root‐morphological characteristics of the natural nickel (Ni) hyperaccumulator Thlaspi goesingense Hálácsy. Plant samples were collected from a serpentine site near Redlschlag (East Austria), characterized by large soil Ni concentrations. Roots were evaluated for mass, length, surface area, diameter, and related ratios using an image‐analysis approach. Results showed that on the indigenous site, T. goesingense Hálácsy developed a fine‐branched root system, confined within a shallow soil depth. Coarse roots (>1 mm) accounted for about 60% of the total root mass (fresh and dry), while their contribution to the surface area and especially to the length of the system was small. Conversely, fine roots (<1 mm) represented 99% of the total root length and 88% of the surface area. The largest proportion of root length and area was found in the smallest diameter class of 0.0 to 0.5 mm. Shoot‐biomass production per unit root was high, in spite of the adverse soil conditions. Roots accounted for 8% of the total plant mass and about 4% of the total Ni accumulation. We conclude that the root system of natively grown T. goesingense Hálácsy exhibits a potential for enhanced Ni extraction from soil, since it mainly consists of very fine roots with extended absorptive area.
Anwendbarkeit geophysikalischer Prospektionsmethoden zur Bestimmung von Bodenverdichtungen und Substratheterogenitäten landwirtschaftlich genutzter Flächen
Authors: Petersen Hauke , Fleige Heiner , Rabbel Wolfgang , Horn Rainer
Published: February 2005

Der Einsatz zunehmend schwerer Landtechnik bei der Bodenbearbeitung kann nachhaltig wirkende Bodenverdichtungen bzw. Bodenverformungen bis in den Unterbodenbereich (Tiefe > 30 cm) unterhalb des Bearbeitungshorizonts verursachen. Bei derartig verdichteten Böden sind Bodenfunktionen wie Wasser‐ und Luftleitfähigkeiten vermindert, so dass sich die Bedingungen für das Pflanzenwachstum verschlechtern und die Böden in ihrer natürlichen Regelungsfunktion beeinträchtigt werden können. Um Gegenmaßnahmen treffen zu können, ist also die Kenntnis des Verdichtungszustands im Boden notwendig.

Da der Verdichtungszustand bisher nur punktuell durch aufwändige Messungen im Labor oder mit geringerer Genauigkeit im Feld bestimmt werden kann, stellt sich die Frage nach einem leistungsfähigen flächenhaften Kartierverfahren. Die prinzipielle Anwendbarkeit verschiedener geophysikalischer Prospektionsverfahren sollte auf diese bodenkundliche Fragestellung hin untersucht werden. Dazu wurden auf einem konventionell bewirtschafteten Jungmoränenstandort in Schleswig‐Holstein vergleichende bodenkundliche und geophysikalische Messungen durchgeführt. Folgende geophysikalische Verfahren kamen zum Einsatz: Georadar (GPR – Ground Penetrating Radar) im Frequenzbereich 500 MHz und 900 MHz, ergänzt durch induktive Leitfähigkeitsmessungen mit dem EM38 einerseits sowie hochauflösende Kompressions‐ und Scherwellenseismik andererseits. Substratheterogenitäten im Unterboden zeichneten sich in allen hier angewandten Verfahren ab, so dass Standorte mit höherer Verdichtungsempfindlichkeit (lehmige Böden) von Standorten mit geringerem Verdichtungspotenzial (sandige Böden) unterschieden werden konnten. Die Radardaten zeigten bei Feldkapazität starke Reflexionen in einer Tiefe von ca. 30 cm, die im Sommer bei trockenen Bedingungen nicht mehr zu beobachten waren. Diese zeitliche Variation der Radarsig‐nale lässt sich durch nur temporär vorhandene Stauwasserbereiche erklären, die auf eine Bodenverdichtung hindeuten können. Seismische Messungen mit Kompressions‐ und Scherwellen wurden entlang kurzer Profillinien (12 m) mit dichtem Sensorabstand (20 cm) durchgeführt. Die gute bis sehr gute Datenqualität dieser Messungen, die sonst für ingenieurgeophysikalische Zwecke eingesetzt werden, zeigt, dass dieses Verfahren auch für bodenkundliche Fragestellungen geeignet ist. Substratvariationen im Unterboden beeinflussten v. a. die Geschwindigkeiten von Kompressionswellen. Ob sich unterschiedlich verdichtete Bereiche detektieren lassen, ist noch offen, da in der Messfläche nur eine gleichmäßig starke Verdichtung des Unterbodens mit geringen Dichtekontrasten bei gleichem Bodentyp vorlag.
Rekonstruktion des Paläomilieus und der Geo‐Pedogenese kalkfreier Marschböden Niedersachsens
Authors: Duntze Oliver , Watermann Frank , Giani Luise
Published: February 2005

Die Genese kalkfreier Marschböden ist nach wie vor strittig. Zur Klärung dieser Frage erfolgte deshalb beispielhaft an zwei Knickmarschen Ostfrieslands die Rekonstruktion ihres Paläomilieus mittels Ergebnissen der Röntgenfluoreszenzspektroskopie, Rasterelektronen‐ und Durchlichtmikroskopie. Profil 1 gliedert sich in sieben Fazies. Die Diatomeenflora deutet auf zeitlich variierende Paläomilieus limnischer, brackischer und mariner Ausprägung hin. Im Grenzbereich von mineralischem Material und Torf sowie im Torf selbst wurden Pyritkristalle gefunden. Die zudem häufig auftretenden engen Zr:Al‐ und Si:Al‐Verhältnisse sowie die engen Ca:Sr‐Verhältnisse weisen auf ruhige, brackische bis lagunäre Sedimentationsbedingungen mit Schilftorfbildung im Rückseitenwatt hin. Profil 2 gliedert sich in zwei Fazies, deren Übergang durch einen plötzlichen Wechsel der Diatomeenzusammensetzung, der geochemischen Eigenschaften und des Carbonatgehalts charakterisiert ist. Die Diatomeenflora und die Ca:Sr‐Verhältnisse der unteren Fazies kennzeichnen ein Priel‐Habitat mit marinem Kontakt und ungewöhnlich engen Si:Al‐ und Zr:Al‐Verhältnissen. Die Ergebnisse lassen vor allem für viele Fazies von Profil 1 auf Entkalkungsprozesse während der Geo‐Pedogenese schließen. Für heute kalkfreie Marschböden gibt es demnach zwei Stadien der Entkalkung, zum einen die frühe Geo‐Pedogenese, wie sie eher für die Knickmarschen Niedersachsens für wahrscheinlich gehalten wird, und zum anderen die spätere terrestrische Entwicklungsphase von der Kalk‐ zur Kleimarsch.
Zusammenhang zwischen hydraulischer und mechanischer Bodenstabilität in Abhängigkeit von der Belastungsdauer
Authors: Fazekas Orsolya , Horn Rainer
Published: February 2005

In Untersuchungen zur Bodenverdichtung wird meist nur die direkte Beziehung zwischen der mechanischen Belastung und der Porenänderung, nicht hingegen die Interaktion zwischen mechanischen und hydraulischen Prozessen als Funktion der Zeitdauer der Belastung bzw. der Häufigkeit der Belastung betrachtet. In der vorliegenden Arbeit wird daher die Beziehung zwischen der Vorbelastung als Maß der mechanischen Stabilität und der Wasserspannungsänderung während einer Belastung analysiert. Die Untersuchungen wurden an gestörtem Bodenmaterial (Ut3) bei einer Anfangslagerungsdichte von 1,4 g cm–3 mit einem Wassergehalt von 25 Gew.% jeweils an vier Parallelproben durchgeführt. Die Bodenproben wurden mit acht verschiedenen Auflasten zwischen 20 und 400 kPa und vier Auflastzeiten (10–240 min) belastet; die Wasserspannungs‐ und die Porenzifferänderungen wurden registriert. Mit steigender Belastungsdauer werden die Proben bei gleicher Auflast intensiver verdichtet. Dadurch sinkt der Wert der Vorbelastung. Gleichzeitig ändert sich während der Belastung die Wasserspannung, denn als Folge der Komprimierung werden die Porenquerschnitte enger und deshalb der Wassersättigungsgrad höher. Damit einher geht je nach verbleibender Bodenfestigkeit auch eine zunehmende Übertragung der mechanischen Auflast auf die flüssige Phase. Dies bedeutet, dass eine Änderung des Porenwasserdruckes von negativ (= Wasserspannung) bis hin zu einem positiven Wert (= Porenwasserüberdruck) reichen kann. Bereits unterhalb des nach Casagrande (1936) berechneten Vorbelastungswertes nimmt der Porenwasserdruck deutlich ab. Die erzielten Ergebnisse zeigen, dass Strukturstabilitätseffekte durch Berücksichtigung der Wasserspannungsänderungen während der Belastung quantifiziert werden müssen, um ein vollständiges Bild der Bodendeformation zu erhalten.
Erosion processes and erodibility of cultivated soils in North Rhine‐Westphalia under artificial rain. I. Site characteristics and results of laboratory experiments
Authors: Kehl Martin , Everding Christoph , Botschek Johannes , Skowronek Armin
Published: February 2005

Soil erosion by water causes substantial on‐site degradation and off‐site damages in the densely populated state of North Rhine‐Westphalia (Germany). Measures of soil conservation should be adjusted to soil erodibilities and should be based on an understanding of the processes involved in water erosion including aggregate breakdown, rainsplash erosion, surface sealing, and soil loss. For a state‐wide assessment of erosion processes and erodibilities, we tested representative cultivated soils of North Rhine‐Westphalia in laboratory and field experiments with artificial rain. In the laboratory experiments described in this paper, rainsplash erosion, sealing susceptibility, and interrill erodibility of 25 topsoils filled in 0.5 m2 boxes were investigated.

Results of different aggregate‐stability tests correlate with organic‐matter contents but not with parameters of rainsplash or soil loss. On most soil materials, rainsplash increases or maintains constant rates in the course of the simulation runs indicating that the soil surface did not attain a higher shear resistance. High sealing susceptibilities are found for soils of quite different textures ranging from loam sand to silt clay, whereas other silt clays, clay loams, and some clay silts maintain high infiltration rates. A trend of increasing sealing susceptibility and total soil loss with increasing clay content is observed for the loam sands to sand loams.

Dynamics of soil loss is largely governed by runoff rates. Total soil loss is also determined by sediment concentration in surface runoff, which is low on most clayey soils, on loam sands poor in clay, and on a sand loam, and high in the case of highly erodible clay silts, loam sands, and sand loams. The most crust prone soils are not necessarily the most erodible.

On most soils, soil‐loss rates do not stabilize until the end of the rainfall experiments. For comparing the interrill erodibilities of the soils, total soil loss is preferred instead of interrill erodibility factors (Ki, Kiq) published in the literature.
Digital soil mapping using artificial neural networks
Authors: Behrens Thorsten , Förster Helga , Scholten Thomas , Steinrücken Ulrich , Spies Ernst‐Dieter , Goldschmitt Michael
Published: February 2005

In the context of a growing demand of high‐resolution spatial soil information for environmental planning and modeling, fast and accurate prediction methods are needed to provide high‐quality digital soil maps. Thus, this study focuses on the development of a methodology based on artificial neural networks (ANN) that is able to spatially predict soil units. Within a test area in Rhineland‐Palatinate (Germany), covering an area of about 600 km2, a digital soil map was predicted. Based on feed‐forward ANN with the resilient backpropagation learning algorithm, the optimal network topology was determined with one hidden layer and 15 to 30 cells depending on the soil unit to be predicted. To describe the occurrence of a soil unit and to train the ANN, 69 different terrain attributes, 53 geologic‐petrographic units, and 3 types of land use were extracted from existing maps and databases. 80% of the predicted soil units (n = 33) showed training errors (mean square error) of the ANN below 0.1, 43% were even below 0.05. Validation returned a mean accuracy of over 92% for the trained network outputs. Altogether, the presented methodology based on ANN and an extended digital terrain‐analysis approach is time‐saving and cost effective and provides remarkable results.
Impact of organic manures with and without mineral fertilizers on soil chemical and biological properties under tropical conditions
Authors: Kaur Kulvinder , Kapoor Krishan K. , Gupta Anand P.
Published: February 2005

Soils receiving organic manures with and without chemical fertilizers for the last 7 yr with pearlmillet–wheat cropping sequence were compared for soil chemical and biological properties. The application of farmyard manure, poultry manure, and sugarcane filter cake alone or in combination with chemical fertilizers improved the soil organic C, total N, P, and K status. The increase in soil microbial‐biomass C and N was observed in soils receiving organic manures only or with the combined application of organic manures and chemical fertilizers compared to soils receiving chemical fertilizers only. Basal and glucose‐induced respiration, potentially mineralizable N, and arginine ammonification were higher in soils amended with organic manures with or without chemical fertilizers, indicating that more active microflora is associated with organic and integrated system using organic manures and chemical fertilizers together which is important for nutrient cycling.
Root growth and N‐uptake activity of oilseed rape (Brassica napus L.) cultivars differing in nitrogen efficiency
Authors: Kamh Mahmoud , Wiesler Franz , Ulas Abdullah , Horst Walter J.
Published: February 2005

Nitrate‐N uptake from soil depends on root growth and uptake activity. However, under field conditions N‐uptake activity is difficult to estimate from soil‐N depletion due to different loss pathways. We modified the current mesh‐bag method to estimate nitrate‐N‐uptake activity and root growth of two oilseed‐rape cultivars differing in N‐uptake efficiency. N‐efficient cultivar (cv.) ‘Apex' and N‐inefficient cv. ‘Capitol' were grown in a field experiment on a silty clayey gleyic fluvisol near Göttingen, northern Germany, and fertilized with 0 (N0) and 227 (N227) kg N ha–1.

In February 2002, PVC tubes with a diameter of 50 mm were installed between plant rows at 0–0.3 and 0–0.6 m soil depth with an angle of 45°. At the beginning of shooting, beginning of flowering, and at seed filling, the PVC tubes were substituted by PVC tubes (compartments) of the same diameter, but with an open window at the upper side either at a soil depth of 0–0.3 or 0.3–0.6 m allowing roots to grow into the tubes. Anion‐exchange resin at the bottom of the compartment allowed estimation of nitrate leaching. The compartments were then filled with root‐free soil which was amended with or without 90 mg N (kg soil)–1. The newly developed roots and nitrate‐N depletion were estimated in the compartments after the installing period (21 d at shooting stage and 16 d both at flowering and grain‐filling stages). Nitrate‐N depletion was estimated from the difference between NO$ _3^- $‐N contents of compartments containing roots and control compartments (windows closed with a membrane) containing no roots. The amount of nitrate leached from the compartments was quantified from the resin and has been taken into consideration in the calculation of the N depletion. The amount of N depleted from the compartments significantly correlated with root‐length density.

Suboptimal N application to the crop reduced total biomass and seed‐yield formation substantially (24% and 38% for ‘Apex’ and ‘Capitol’, respectively). At the shooting stage, there were no differences in root production and N depletion from the compartments by the two cultivars between N0 and N227. But at flowering and seed‐filling stages, higher root production and accordingly higher N depletion was observed at N0 compared to N227. Towards later growth stages, the newly developed roots were characterized by a reduction of root diameter and a shift towards the deeper soil layer (0.3–0.6m). At low but not at high N supply, the N‐efficient cv. ‘Apex’ exhibited higher root growth and accordingly depleted nitrate‐N more effectively than the N‐inefficient cv. ‘Capitol’, especially during the reproductive growth phase. The calculated nitrate‐N‐uptake rate per unit root length was maximal at flowering (for the low N supply) but showed no difference between the two cultivars. This indicated that the higher N‐uptake efficiency of cv. ‘Apex’ was due to higher root growth rather than higher uptake per unit of root length.
Bodensystematik und Bodenklassifikation Teil I: Grundbegriffe
Authors: Albrecht Christoph , Jahn Reinhold , Huwe Bernd
Published: February 2005

Bodenordnungssysteme lassen sich meist nach zwei Prinzipien entwickeln: Entweder werden nur rein bodenkundliche Informationen als kategorisierendes Merkmal verwendet (pedogenetische Faktoren/Prozesse), oder die Kategorienbildung erfolgt problemorientiert anhand ausgewählter Parameter. Die meisten der weltweit verwendeten Bodenordnungssysteme lassen sich nach ihrer Grundausrichtung einem der beiden Typen zuordnen. Diese Betrachtungsweise ist nicht neu und wird in der Literatur mit unterschiedlichen Begriffen und Begriffsinhalten dargestellt.

In der vorliegenden Arbeit werden die verschiedenen Definitionen von Systematik, Klassifikation, Taxonomie und Identifizierung zusammengefasst und geordnet. Dabei fällt auf, dass Begriffe mit sehr unterschiedlichen Inhalten oft synonym verwendet werden.

Grundgedanke unserer Überlegungen ist die Trennung von Systematik, Klassifikation und Identifizierung. Systematik ist die grundsätzliche wissenschaftlich‐deduktive Gliederung von Objekten in systematische Einheiten. Dabei soll das gesamte Wissen eines Fachgebietes in eine überschaubare Form gebracht werden, im Mittelpunkt stehen sowohl die umfassende Beschreibung einzelner Objekte als auch die Beziehungen zwischen den Objekten. Im Gegensatz dazu ist eine Klassifikation die zielorientiert‐induktive Gliederung von Objekten. Die entstehenden Klassen werden nur anhand ausgewählter Parameter abgegrenzt, womit ein schneller Überblick bei speziellen Fragestellungen ermöglicht wird. Die Identifizierung ist die Einordnung von neuen Objekten in eine bestehende Systematik oder Klassifikation.

Eine zweifelsfreie Identifizierung erfordert die Messbarkeit der kategorisierenden Merkmale. Bei einer genetisch angelegten Bodensystematik sind die Merkmale die Boden bildenden Prozesse und Faktoren. Da sie beim gegenwärtigen Kenntnisstand oft nicht messbar sind, bleiben Versuche, einen Boden in eine Systematik einzuordnen, häufig hypothetisch und dadurch subjektiv. Die Ergebnisse einer Bodensystematisierung sind daher oft anfechtbar, weil sie nicht durch Messwerte verifiziert werden können. Im Gegensatz dazu erlauben Bodenklassifikationen objektive Profilansprachen. Da jedoch die Festlegung der Grenzwerte eher pragmatisch nach Zweckmäßigkeit geschieht und nicht wissenschaftlich anhand von Prozessintensitäten, ist die Verwendung als grundlegendes Ordnungssystem eines Wissenschaftsgebietes nicht möglich.

Die Bodenkunde benötigt beide Arten von Ordnungssystemen, um wissenschaftliche und praktische Ansprüche gleichermaßen erfüllen zu können, jedoch erfordern die Vollendung und Verifizierung der Systematik umfangreiche Forschungsarbeiten. Kurzfristig ist dieses Problem nur durch die Entwicklung einer kennwertbasierten Klassifikation lösbar, mit der die Kategorien der bestehenden Systematik so gut wie möglich nachgebildet werden. Langfristig ist die exakte Erforschung und Modellierung der Boden bildenden Prozesse aber unumgänglich.
Pyrene End‐Labeled Diblock Glycopolymers: Synthesis and Aggregation
Authors: Lu Feng‐Zhu , Meng Jian‐Qiang , Du Fu‐Sheng , Li Zi‐Chen , Zhang Bao‐Yan
Published: February 2005

Summary: A pyrene end‐labeled amphiphilic block copolymer, poly(ε‐caprolactone)‐block‐poly[6‐O‐(4‐vinylbenzyl)‐D‐galactose] (Py‐PCL‐b‐PVBG), was synthesized by a four‐step method. The aggregation behavior of the diblock copolymer in solution was studied by monitoring the fluorescence of pyrene. TEM measurements revealed that the aggregates obtained by first dissolving the copolymer in N,N‐dimethylformamide (DMF), followed by the addition of water, were primarily spheres with the PCL blocks in the core. The PVBG corona was then crosslinked with glutaraldehyde. Final removal of the PCL core was accomplished by degradation under basic conditions, which resulted in the formation of hollow glycopolymer nanospheres.

Structure of poly(ε‐caprolactone)‐block‐poly[6‐O‐(4‐vinylbenzyl)‐D‐galactose].

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Structure of poly(ε‐caprolactone)‐block‐poly[6‐O‐(4‐vinylbenzyl)‐D‐galactose].
Organic‐Inorganic Hybrid Membranes for Removal of Benzene from an Aqueous Solution by Pervaporation
Authors: Ohshima Tadahiro , Matsumoto Moritoshi , Miyata Takashi , Uragami Tadashi
Published: February 2005

Summary: Preparation of organic‐inorganic hybrid membranes and their pervaporation permeation and separation characteristics for an aqueous solution of 0.05 wt.‐% benzene are described. In this study, we prepared organic‐inorganic hybrid membranes by the sol‐gel reaction of tetraethoxysilane (TEOS) as an inorganic component with poly(methyl methacrylate‐co‐vinyltriethoxysilane) (P(MMA‐co‐VTES)) and poly(butyl methacrylate‐co‐vinyltriethoxysilane) (P(BMA‐co‐VTES)) as organic components. When an aqueous solution of dilute benzene (0.05 wt.‐%) was permeated through the P(MMA‐co‐VTES)/TEOS and P(BMA‐co‐VTES)/TEOS hybrid membranes, the benzene concentration in the permeate through all hybrid membranes was higher than that in the feed solution. This result demonstrates that these hybrid membranes are benzene selective for an aqueous solution containing dilute benzene. The benzene/water selectivity of the P(BMA‐co‐VTES)/TEOS hybrid membrane was about 20 times higher than that of the P(MMA‐co‐VTES)/TEOS hybrid membrane. Specifically, the P(BMA‐co‐VTES)/TEOS hybrid membrane with a TEOS content of 75 mol‐% showed the highest benzene/water selectivity. The benzene/water selectivity of the hybrid membranes depended significantly on the cross‐linked structures formed by the sol‐gel reaction of VTES and TEOS.

Effects of the TEOS content on the sorption selectivity (○) and the diffusion selectivity (•) for an aqueous solution of 0.05 wt.‐% benzene through P(MMA‐co‐VTES)/TEOS and P(BMA‐co‐VTES)/TEOS hybrid membranes at 40 °C.

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Effects of the TEOS content on the sorption selectivity (○) and the diffusion selectivity (•) for an aqueous solution of 0.05 wt.‐% benzene through P(MMA‐co‐VTES)/TEOS and P(BMA‐co‐VTES)/TEOS hybrid membranes at 40 °C.
Morphological and Rheological Properties of Polyamide 6/Poly(propylene)/Organoclay Nanocomposites
Authors: Chow Wen Shyang , Mohd Ishak Zainal A. , Karger‐Kocsis József
Published: February 2005

Summary: Polyamide 6 (PA6)/Poly(propylene) (PP)/organoclay (octadecylamine intercalated montmorillonite) systems with and without compatibilizer (maleated poly(propylene) and ethylene/propylene‐based rubber (PPgMA and EPRgMA, respectively)) were produced by extrusion melt blending and the clay dispersion was characterized by transmission electron microscopy (TEM) and X‐ray diffraction (XRD). The rheological behaviour of the nanocomposites was determined by various methods, viz melt flow index (MFI), capillary and plate/plate rheological measurements. Attempts were made to trace the rheological parameters that reliably reflect the observed changes in the clay dispersion. It was found that some parameters in the viscoelastic range derived from frequency sweep measurements using a plate/plate rheometer are a suitable indicator for changes in the clay dispersion. High initial viscosity with a strong reduction as a function of frequency was attributed to improved clay exfoliation. The latter was also reflected by a high initial shear storage modulus (G′) along with its small change with the frequency.

Variation of the storage modulus (G′) as a function of frequency for the PA6/PP nanocomposites. Note: this figure also indicates how the slopes at low and high shear rates were determined.

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Variation of the storage modulus (G′) as a function of frequency for the PA6/PP nanocomposites. Note: this figure also indicates how the slopes at low and high shear rates were determined.
Ink‐Jet Printing of Electron Donor/Acceptor Blends: Towards Bulk Heterojunction Solar Cells
Authors: Marin Veronica , Holder Elisabeth , Wienk Martijn M. , Tekin Emine , Kozodaev Dmitry , Schubert Ulrich S.
Published: February 2005

Summary: We illustrate the ink‐jet printing of a thin‐film library of donor/acceptor systems useful in bulk heterojunction solar cells and their characterization utilizing a UV‐vis/fluorescence plate reader and an optical profilometer. In addition, the morphology of the films has been examined by atomic force microscopy (AFM). The ink‐jet processing technology allows printing of arrays of different donor/acceptor compositions on one substrate as well as the subsequent fast optical screening of the electron transfer processes. The investigated films consist of blends of a poly(methyl methacrylate) polypyridyl ruthenium(II) copolymer (RuPMMA) as electron donor material (p‐type) and C60 fullerene (PC60BM) as well as heptyl viologen (C7‐V) derivatives as electron acceptor materials (n‐type).

Ink‐jet printing process and investigated donor/acceptor pair (RuPMMA‐PC60BM).

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Ink‐jet printing process and investigated donor/acceptor pair (RuPMMA‐PC60BM).
Evolution and Operating Experiences with Different Drop‐On‐Demand Systems
Authors: Burgold Jörg , Weise Frank , Fischer Michael , Schlingloff Gregor , Henkel Thomas , Albert Jens , Mayer Günther , Schober Andreas
Published: February 2005

Summary: We describe the development of different drop‐on‐demand systems particularly for applications for the liquid handling of biopolymers. Different designs of drop‐on‐demand systems developed by the authors are described. Experiments with these systems show the applicability for pipetting different liquids with different properties. Commercially available systems are also tested. A comparison of the different approaches leads to a discussion of the best fields of application of the different approaches or, alternatively, to the potential further development of the drop‐on‐demand technologies.

Principle setup of the print heads.

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Principle setup of the print heads.
Morphology of Symmetric Diblock Copolymers Confined Between Two Stripe‐Patterned Surfaces – Tilted Lamellae and More
Authors: Wang Qiang
Published: February 2005

Summary: We report the first Monte Carlo simulations on the thin‐film morphology of symmetric diblock copolymers confined between either symmetrically or antisymmetrically stripe‐patterned surfaces. Under suitable surface configurations (where the lamellae can comply with the surface patterns and can have a period close to the bulk lamellar period L0), tilted lamellae are observed for film thicknesses D ≥ 2L0; the checkerboard morphology is obtained for smaller film thicknesses. The A‐B interfaces in the tilted lamellae are basically perpendicular to the surfaces in their immediate vicinity, and exhibit undulations away from them. In some cases, the severe frustration imposed by the two patterned surfaces leads to irregular or unexpected morphologies, which represent locally stable states. The efficient sampling of our expanded grand‐canonical Monte Carlo technique enables us to observe more than one locally stable morphologies and the flipping between them during a single simulation run.

Tilted lamellae between symmetrically patterned surfaces (perpendicular to z) with a surface pattern period of 1.5L0 and a film thickness of 2.67L0. L0 is the bulk lamellar period and the black curves mark the A‐B interfaces.

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Tilted lamellae between symmetrically patterned surfaces (perpendicular to z) with a surface pattern period of 1.5L0 and a film thickness of 2.67L0. L0 is the bulk lamellar period and the black curves mark the A‐B interfaces.
Toward a Cohesive Theory of Polymerization Volume Change, 1
Authors: Holder Andrew J. , Kilway Kathleen V. , Code James E. , Giese Gregory J. , Travis DeAnna M. , Fleckenstein Jamie E. , Marzluf Kathleen R. , Clevenger Robert C. , Vastlik Heather L. , Eick J. David , Chappelow Cecil C.
Published: February 2005

Summary: Rational design of polymer‐based composites must include an understanding of how and why polymerization volume change occurs. Computational chemistry methods offer significant leverage in such processes. An obstacle to their use has been the meager amount of systematic volume change data collected under the same conditions and using the same methods. This work provides volume change data for eight oxiranes using the mercury dilatometry method. Densities of pure monomers are often unknown for newly synthesized compounds, but are required for the correction of the composite to monomer volume change. The densities have been estimated here by the application of a newly‐developed quantum mechanically‐based quantitative structure property relationship (QMQSPR). This computational chemistry model can be used to estimate densities of a large array of organic compounds with sufficient accuracy for most routine purposes. These results are presented herein.

Correspondence between experimental and QMQSPR calculated results for densities.

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Correspondence between experimental and QMQSPR calculated results for densities.
Addition‐Fragmentation Chain Transfer to Polymer in the Free Radical Ring‐Opening Polymerization of an Eight‐membered Cyclic Allylic Sulfide Monomer
Authors: Phelan Marisa , Aldabbagh Fawaz , Zetterlund Per B. , Yamada Bunichiro
Published: February 2005

Summary: A detailed investigation of chain transfer to polymer during free radical ring‐opening polymerization of the eight‐membered disulfide monomer 2‐methyl‐7‐methylene‐1,5‐dithiacyclooctane (MDTO) is presented. It has been shown that extensive chain transfer to polymer occurs involving both poly(MDTO) radicals and cyanoisopropyl radicals. Significant decreases in molecular weight were observed when cyanoisopropyl radicals were generated in the presence of poly(MDTO) in the absence of monomer. The molecular weight distribution (MWD) obtained from polymerization of MDTO in the presence of pre‐added poly(MDTO) was markedly different from that obtained without pre‐added polymer. A kinetic model was constructed in an attempt to quantitatively describe the chain transfer to polymer process based on the addition fragmentation chain transfer mechanism. It was found however that the simulated MWDs were considerably broader than the experimental MWDs, which were similar to the Schulz‐Flory distribution.

Mechanism for chain transfer to polymer.

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Mechanism for chain transfer to polymer.
Smell identification ability in twin pairs discordant for Parkinson's disease
Authors: Marras Connie , Goldman Samuel , Smith Amanda , Barney Peter , Aston Diana , Comyns Kathleen , Korell Monica , Langston J. William , Ross G. Webster , Tanner Caroline M.
Published: February 2005

Olfactory dysfunction has been proposed to be a sign that may precede the motor features of Parkinson's disease (PD). To determine whether smell identification deficits predict subsequent PD, we studied smell identification ability using the University of Pennsylvania Smell Identification Test (UPSIT) in 62 members of male twin pairs discordant for PD at baseline. Smell identification ability was reduced at baseline in the twins with PD compared to their unaffected brothers (23 vs. 31 of 40; P = 0.001). UPSIT scores were not reduced in the twins without PD when compared to age‐ and gender‐specific normal values. After a mean interval of 7.3 years, 28 unaffected twins were still alive and 19 agreed to a second evaluation. Two had newly developed PD. Neither twin had impaired smell identification at baseline. The average decline in UPSIT percentile scores in these 2 twins was greater than in the 17 twins who did not develop PD (−68% vs. −24%; P = 0.01). In subjects who did not meet Core Assessment Program for Intracerebral Transplantations diagnostic criteria for PD at baseline, the presence of cardinal signs of parkinsonism was not associated with lower baseline UPSIT scores nor with a subsequent decline. Smell identification ability may not be a sensitive indicator of future PD 7 or more years before the development of motor signs, even in a theoretically at‐risk population. © 2005 Movement Disorder Society
Random disambiguation paths for traversing a mapped hazard field
Authors: Priebe Carey E. , Fishkind Donniell E. , Abrams Lowell , Piatko Christine D.
Published: February 2005

We consider the problem of safely and swiftly navigating through a spatial arrangement of potential hazard detections in which each detection has associated with it a probability that the detection is indeed a true hazard. When in close proximity to a detection, we assume the ability—for a cost—to determine whether or not the hazard is real. Our approach to this problem involves a new object, therandom disambiguation path(RDP), which is a curve‐valued random variable parametrized by a binary tree with particular properties. We prove an admissibility result showing that there is positive probability that the use of an RDP reduces the expected traversal length compared to the conventional shortest zero‐risk path, and we introduce a practically computable additive‐constant approximation to the optimal RDP. The theoretical considerations are complemented by simulation and example. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005
A non‐reflecting layer method for non‐linear wave‐type equations on unbounded domains with applications to shape memory alloy rods
Authors: Newman M. , Safjan A. , Popov P. , Lagoudas D. C.
Published: February 2005

In this paper a new technique is introduced and applied in solving one‐dimensional linear and non‐linear wave‐type equations on an unbounded spatial domain. This new technique referred to as the non‐reflecting layer method (NRLM) extends the computational domain with an artificial layer on which a one‐way wave equation is solved. The method will be applied to compute stress waves in long rods consisting of NiTi shape memory alloy material subjected to impact loading and undergoing detwinning and pseudo‐elastic material responses. The NRLM has been tested on model problems and it has been found that the computed solutions agree well with the exact solutions, i.e. normalized error levels are in ranges acceptable for engineering computations. Copyright © 2005 John Wiley & Sons, Ltd.
Exponential finite elements for diffusion–advection problems
Authors: El‐Zein Abbas
Published: February 2005

A new finite element method for the solution of the diffusion–advection equation is proposed. The method uses non‐isoparametric exponentially‐varying interpolation functions, based on exact, one‐ and two‐dimensional solutions of the Laplace‐transformed differential equation. Two eight‐noded elements are developed and tested for convergence, stability, Peclet number limit, anisotropy, material heterogeneity, Dirichlet and Neumann boundary conditions and tolerance for mesh distortions. Their performance is compared to that of conventional, eight‐ and 12‐noded polynomial elements.

The exponential element based on two‐dimensional analytical solutions fails basic tests of convergence. The one based on one‐dimensional solutions performs particularly well. It reduces by about 75% the number of elements and degrees of freedom required for convergence, yielding an error that is one order of magnitude smaller than that of the eight‐noded polynomial element. The exponential element is stable and robust under relatively high degrees of heterogeneity, anisotropy and mesh distortions. Copyright © 2005 John Wiley & Sons, Ltd.