bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wirkung des Mikroreliefs auf die räumliche Variabilität des Kohlenstoffgehaltes eines Podzoluvisols in einem Dauerdüngungsversuch
Authors: Kuzyakova Irina F. , Kuzyakov Yakov V. , Thomas Erhard 
Published: February 2007

AbstractDie Wirkung eines schwach ausgeprägten Mikroreliefs auf die räumliche Verteilung und Variabilität des Kohlenstoffgehaltes (Ct) im Boden eines in der Nähe von Moskau liegenden Dauerversuches wurde mit Hilfe von geostatistischen Methoden untersucht. Es wurde festgestellt, daß sich nur 20% der Ct‐Variabilität durch die Wirkung agrogener Faktoren erklären lassen. Um den Einfluß des Mikroreliefs auf Ct analysieren und statistisch nachweisen zu können, wurde eine Reliefformalisierung durchgeführt. Sie umfaßt die Bestimmung der lokalen Neigung, der lokalen Wassereinzugsgebiete, der lokalen relativen Intensität der temporären Wasserströme sowie die Differenzierung konvexer und konkaver Reliefformen. Durch Kriging mit verschiedenem Abstand zwischen den Blockzentren wurden Reliefformen verschiedener Ordnung bestimmt. Die Parameter des formalisierten Reliefs wurden mit dem Ct des Bodens anhand von Variogrammen und Korrelationen verglichen. Die Kombination der Reliefparameter ermöglicht die Einteilung des Feldes in einzelne Teilflächen, die durch verschiedene Korrelations‐ und Wirkungstypen charakterisiert sind. So führen die Reliefsammelformen mit maximalen Werten der Intensität der relativen Wasserströme und die konvexen Reliefformen mit ansteigender Intensität zur Ct‐Verringerung. Die Ct‐Akkumulation findet vor allem in den Übergangspositionen zwischen konvexen und konkaven Reliefformen mit mittlerer Intensität statt.
Beschreibung des Verlaufs der Stickstoffaufnahme von Kohlrabi (Brassica oleracea convar. acephala var. gongylodes L.) mit Hilfe von Wachstumsstadien und eines empirischen Wachstumsmodells
Authors: Feller Carmen , Fink Matthias 
Published: February 2007

AbstractIm Freilandgemüsebau werden Düngungsberatungssysteme verwendet, deren Empfehlungen auf geschätzten Verläufen der Stickstoffaufnahme beruhen. Da die Schätzung der Stickstoffaufnahme möglichst genau sein sollte, werden 3 Schätzmethoden und deren Genauigkeit (Standardfehler der Differenz von Meßwert und Schätzwert, sd) verglichen. Als Datengrundlage werden die in 16 Feldversuchen gemessenen Verläufe der Stickstoffaufnahme von Kohlrabi (Brassica oleracea var. gongylodes L.) verwendet.Die Nutzung von beobachteten Wachstumsstadien ergab den kleinsten Schätzfehler (sd = 14 kg N · ha−1). Diese Methode ist für die praktische Anwendung empfehlenswert, da sie einfach und genau ist. Die Verwendung eines empirischen Modells der Stickstoffaufnahme (sd = 16 kg N · ha−1) ist mit mehr Aufwand verbunden. Eine Schätzung in Abhängigkeit von der Zeit nach der Pflanzung ist besonders einfach, weist jedoch den größten Schätzfehler (sd = 28 kg N · ha−1) auf.
Characterization of phytoavailable zinc in compost‐peat substrates — Comparison of methods
Authors: Bucher Annette S. , Schenk Manfred K. 
Published: February 2007

AbstractCompost of separately collected green yard and organic household wastes may contain high amounts of Zn. Hence, substrates basing on compost can result in Zn phytotoxicity. The aim of the investigations was to identify a suitable reagent to characterize phytoavailable Zn in compost‐peat substrates. Petunia hybrids were cultivated in compost‐peat substrates with increasing Zn amounts (basic load, 400, 800, 1600 mg kg−1 d.m. aqua regia soluble). Extractable Zn was determined by extraction of fresh and dried substrates with H2O, 1 M NH4NO3, 0.1 M CaCl2, 1 M NH4OAc, and CaCl2‐DTPA (0.01 M + 0.002 M). The Zn content of plants increased significantly with increasing Zn application and decreasing pH. The result of CaCl2 and NH4OAc extraction reflected the influence of pH on Zn phytoavailability quite well and the correlation with the plant Zn content was very good. Extraction with H2O and NH4NO3 did not give acceptable results. Extraction with CaCl2‐DTPA was inconsistent for all trials and thus not suitable. The percentage of CaCl2‐extractable Zn in relation to the aqua regia soluble content at the same pH varied over the trials. Thus, the phytoavailable content of the substrates is influenced by additional factors, besides Zn supply and pH. The result of CaCl2 extraction of dried substrates resulted in the best reflection of Zn phytoavailability and was used for all further investigations, including determination of critical values of phytotoxic Zn. Plant yield was not influenced by the Zn treatments. However, Zn induced chlorosis of petunias occurred at a plant Zn content > 160 mg kg−1 d.m. and a phytoavailable Zn content in the substrate > 6 mg l−1 in CaCl2 extract and > 2.6 mg l−1 in NH4OAc extract, respectively.
Räumliche Variabilität und Verteilung von Schwermetallen in den Böden einer 1 km2 großen Modellfläche im Siegerland
Authors: Geiler Holger , Aschenbrenner Frank , Denge Hildegard S. , Donsbach Alexander , Ostermann Rüdiger , Knoblich Klaus , Maurer Wolfgang 
Published: February 2007

AbstractAusgehend von einer 1 km2 großen Modellfläche, deren Böden in Anlehnung an ein empirisches Konzept beprobt wurden, wird eine Analyse der Schwermetallgehalte durchgeführt. Das Gebiet steht nicht unter dem unmittelbaren Einfluß industrieller Belastungen. Den tieferen Untergrund bilden unterdevonische Gesteine, die überwiegend mit Tonschiefern, untergeordnet mit Sandsteinen, vertreten sind. Der Oberflächenbewuchs besteht aus Wald (Nadel‐ und Laubwald) mit nur wenigen Wiesenflächen. Um die räumliche Schwermetallverteilung in dem weitgehend homogenen und ausreichend großen Gebiet zu untersuchen, sind an jeweils 100 Bodenproben aus drei verschiedenen Entnahmetiefen (bis max. 1 m) neben pH‐Wert und organischer Substanz die Gesamtgehalte nach Königswasseraufschluß von Cadmium, Chrom, Kupfer, Nickel, Blei und Zink ermittelt worden. Aus den vertikalen und horizontalen Verteilungsmustern der Schwermetalle im Boden lassen sich Rückschlüsse auf Gesteinsinhomogenitäten oder Verlagerungsvorgänge und Bindungsformen ziehen. Semivariogramme der Schwermetallgehalte wurden ermittelt und die flächenhafte Verteilung der Schwermetalle mittels Kriging geschätzt. Es wird die Möglichkeit untersucht, repräsentative Aussagen über die Verteilungen der verschiedenen Metalle zu erhalten und Vorschläge zur Optimierung von Probenahmerastern für bestimmte Genauigkeitsansprüche flächendeckender Bewertungen erarbeitet.
Vereinfachte Bestimmung der Basenneutralisationskapazität (BNK) stark saurer Böden
Authors: Böttcher Jürgen , Lauer‐Thiemecke Stefan 
Published: February 2007

AbstractDie Basenneutralisationskapazität (BNK) ist ein wichtiges chemisches Charakteristikum saurer Böden. Sie kann zuverlässig mit Titrationsmethoden (BNKtit) bestimmt werden, die jedoch sehr arbeitsaufwendig sind und viel Bodenprobenmaterial erfordern, das bei Bohrstockbeprobung (Kartierung, Flächenuntersuchung) meist nicht zur Verfügung steht. Da vorhandene Puffermethoden, die mit weniger Bodenmaterial auskommen, einige Nachteile haben, wurde die bekannte Schachtschabel‐Methode mit Ca‐Acetat‐Puffer für die Anwendung auf stark versauerte Böden weiterentwickelt. Meßwerte der erarbeiteten Ca‐Acetat‐Methode (BNKac) stimmten bei der Überprüfung an Mineralböden (n = 59) fast ideal mit denen der BNKtit überein. Bei Auflagehumus (n = 10) ergab sich im Mittel eine geringfügige Überschätzung der BNKtit durch die BNKac, die jedoch immer < 10% war. Auch bei sehr geringer Bodeneinwaage, weitem Boden: Lösungs‐Verhältnis und Integration der pH(H2O)‐Messung in die BNKac‐Ermittlung können zuverlässige BNK‐Werte ermittelt werden. Die BNKac‐Methode kann als einfache und zuverlässige Methode für die Ermittlung der BNK an kleinen Bodenprobenmengen empfohlen werden.
Improving the fatty acid composition of corn oil by using germplasm introgression
Authors: White Pamela J. , Pollak Linda M. , Duvick Susan 
Published: February 2007

AbstractThe general public has shown increasing interest in consuming oils that are beneficial to health. Thus, oil from corn (Zea mays L.), along with most major edible oils, has been the target of genetic alterations to improve the fatty acid composition. The fatty acid profile goals vary, depending upon the intended use for the oil. We have targeted the development of corn oil with 1) low total saturated fatty acids, 2) high total saturated fatty acids, and 3) mid‐oleic acid, in each case via two different sources: exotic germplasm identified through an international program to broaden the corn germplasm base and introgression of a wild, grassy relative of corn, Tripsacum (Tripsacum dactaloides L). We have been successful at identifying corn lines with each of the noted traits.
Elimination of spin diffusion effects in saturation transfer experiments: application to hydrogen exchange in proteins
Authors: Jensen Malene Ringkjøbing , Kristensen Søren M. , Led Jens J. 
Published: February 2007

AbstractThe NMR saturation transfer experiment is widely used to characterize exchange processes in proteins that take place on the ms‐s timescale. However, spin diffusion effects are inherently associated with the saturation transfer experiment and may overshadow the effect of the exchange processes of interest. As shown here, the effects from spin diffusion and exchange processes can be separated by varying the field strength of the saturation pulse, thereby allowing correct exchange rates to be obtained. The method is demonstrated using the hydrogen exchange process in the protein Escherichia coli thioredoxin as an example. Copyright © 2007 John Wiley & Sons, Ltd.
Unambiguous structural characterization of hydantoin reaction products using 2D HMBC NMR spectroscopy
Authors: Senior Mary M. , Chan Tze‐Ming , Li Guoqing , Huang Ying , Stamford Andrew 
Published: February 2007

AbstractData from two‐dimensional (2D) NMR experiments were used to identify the reaction products resulting from the opening of pyroglutamates with isocyanates or thioisocyanates. The reaction has the potential to produce compounds that would have very similar one–dimensional proton (1H) or carbon–13 (13C) NMR spectra. Careful analysis of 1H1H COSY, 1H1H NOESY, and HMBC data, including chemical shifts and coupling constants, were used to distinguish correctly between carbamoyl‐2‐pyrrolidinone, hydantoin, and perhydro‐1,3‐diazepine‐2,4‐dione type structures that could result from this reaction. This work describes their preparation and subsequent identification using 2D NMR spectroscopy, and includes complete 13C assignments of the reaction products. The 2D NMR techniques and analysis described here can be applied successfully to other synthetic reactions with the potential to produce isomeric products. Copyright © 2007 John Wiley & Sons, Ltd.
Postural response of the pelvic floor and abdominal muscles in women with and without incontinence
Authors: Smith Michelle D. , Coppieters Michel W. , Hodges Paul W. 
Published: February 2007

AbstractAimsTo determine whether activity of the pelvic floor (PF) and abdominal muscles differs between continent and incontinent women in response to a postural perturbation with a moderately full or empty bladder.MethodsElectromyographic (EMG) activity of the PF and abdominal muscles was recorded with surface electrodes prior to and after a postural perturbation in which a 1 kg weight was dropped 30 cm into a bucket held by the subject. Perturbations were applied to the trunk in trials in which the timing of the weight drop was unknown (unexpected) or predictable (expected). Trials were performed with the bladder empty, and when the subject reported a sensation of moderate bladder fullness after drinking between 200 and 1,000 ml of water.ResultsWomen with incontinence demonstrated increased PF EMG compared to continent women both prior to and during the postural response associated with unexpected loading. In addition, obliquus externus abdominis EMG was increased in incontinent women during these trials. When the bladder was moderately full, PF EMG decreased, whereas abdominal muscle EMG tended to increase.ConclusionsThese data suggest that women with incontinence have increased PF and abdominal muscle activity associated with postural perturbations. This finding challenges the clinical assumption that incontinence is associated with reduced PF muscle activity, and suggests that training control and coordination of abdominal muscle activity may be important in treatment of this condition. The contrasting effects of increased bladder volume on PF and abdominal muscle EMG are likely to present further challenges to the maintenance of continence. Neurourol. Urodynam. 26:377–385, 2007. © 2007 Wiley‐Liss, Inc.
Electrical stimulation of sacral dermatomes in multiple sclerosis patients with neurogenic detrusor overactivity
Authors: Fjorback M.V. , Van Rey F.S. , Rijkhoff N.J.M. , Nøhr M. , Petersen T. , Heesakkers J.P. 
Published: February 2007

AbstractAimsTranscutaneous electrical stimulation of the dorsal penile/clitoral nerve (DPN) has been shown to suppress detrusor contractions in patients with neurogenic detrusor overactivity (NDO). However, the long‐term use of surface electrodes in the genital region may not be well tolerated and may introduce hygienic challenges. The aim of this study was to assess whether electrical stimulation of the sacral dermatomes could suppress detrusor contractions in multiple sclerosis (MS) patients with NDO, hereby providing an alternative to DPN stimulation.Materials and MethodsA total of 14 MS patients (8 M, 6 F) with low bladder capacity (<300 ml) and a recent urodynamic study showing detrusor overactivity incontinence participated in the study. Three successive slow fill cystometries (16 ml/min) were carried out in each patient. The first filling served as control filling where no stimulation was applied. In the second and third filling electrical stimulation of either the DPN or sacral dermatomes was applied automatically whenever the detrusor pressure exceeded 10 cmH2O.ResultsThe control filling showed detrusor overactivity in 12 of the 14 patients. In 10 of the 12 patients one or more detrusor contractions could be suppressed with DPN stimulation. Electrical stimulation of the sacral dermatomes failed to suppress detrusor contractions in all patients.ConclusionsAlthough therapeutic effects may be present from stimulation of the sacral dermatomes, we were unable to demonstrate any acute effects during urodynamics. For this reason stimulation of the sacral dermatomes is not an option in a system that relies on the acute suppression of a detrusor contraction. Neurourol. Urodynam. 26:525–530, 2007. © 2007 Wiley‐Liss, Inc.
Changes in T‐type calcium channel and its subtypes in overactive detrusor of the rats with partial bladder outflow obstruction
Authors: Li Longkun , Jiang Chonghe , Hao Ping , Li Weibing , Fan Lixin , Zhou Zhansong , Song Bo 
Published: February 2007

AbstractAimsTo investigate the activity of the T‐type calcium channel (TCC) and the expression of its subtypes in overactive detrusor (OD) myocytes in rats after partial bladder outflow obstruction (PBOO).MethodsThirteen male Wistar rats with OD after PBOO (OD group) and eight sham‐operated rats (control group) were studied. The two groups were compared regarding the expression of TCC subtype genes by reverse transcription‐polymerase chain reaction (RT‐PCR) and the TCC kinetics and cell action potential by whole‐cell patch‐clamp.ResultsThe time course and density of the current were significantly higher in the OD cells than those in the control detrusor. Whole‐cell patch‐clamp analysis showed that the activation of TCCs in detrusor myocytes in the OD group was faster than the control group, but inactivation was almost the same in both groups, suggesting a significant enhancement of the Ca2+ “window” current in the OD group. Patch‐clamp recording of action potentials in the OD cells indicated an increase in excitability and a decrease in the repolarization interval. RT‐PCR assay showed an abnormal expression of α1G subtype in the OD cells.ConclusionsTCCs could be one of the crucial factors for the abnormal excitation in OD cells. The development of OD after PBOO presumably relates to the increase in TCC current in the bladder cells, the enhancement of the Ca2+ “window” current for Ca2+ inflow, the prolongation of the intracellular calcium oscillations, and the acceleration of the cell depolarization. Neurourol. Urodynam. 26:870–878, 2007. © 2007 Wiley‐Liss, Inc.
An adaptive remeshing strategy for flows with moving boundaries and fluid–structure interaction
Authors: Saksono P. H. , Dettmer W. G. , Perić D. 
Published: February 2007

AbstractThe primary objective of this work is to extend the capability of the arbitrary Lagrangian–Eulerian (ALE)‐based strategy for solving fluid–structure interaction problems. This is driven by the fact that the ALE mesh movement techniques will not be able to treat problems in which fluid–structure interface experiences large motion. In addition, for certain problems the need arises to capture accurately flow features, such as a region with high gradients of the solution variables. This can be achieved by incorporating an adaptive remeshing procedure into the solution strategy.As in our previous works (Comput. Methods Appl. Mech. Eng. 2006; 195:1633–1666; Comput. Methods Appl. Mech. Eng. 2006; 195:5754–5779), here, the fluid flow is governed by the incompressible Navier–Stokes equations and modelled by using stabilized low order velocity–pressure finite elements. The motion of the fluid domain is accounted for by an arbitrary Lagrangian–Eulerian (ALE) strategy. The flexible structure is represented by means of appropriate standard finite element formulations while the motion of the rigid body is described by rigid body dynamics. For temporal discretization of both fluid and solid bodies, the discrete implicit generalized‐α method is employed. The resulting strongly coupled set of non‐linear equations is then solved by means of a novel partitioned solution procedure, which is based on the Newton–Raphson methodology and incorporates full linearization of the overall incremental problem.Within the adaptive solution strategy, the quality of fluid mesh and the solution quality indicator are evaluated regularly and compared against the appropriate remeshing criteria to decide whether a remeshing step is required. The adaptive remeshing procedure follows closely the standard computational procedure in which the adaptive remeshing process produces a mesh that can capture salient features of the flow field. For the problems under consideration in this work the motion of the fluid boundary very often results in boundaries with very high curvatures and a fluid domain that contain areas with small cross‐sections. To be able to generate meshes that give result with acceptable accuracy these local geometrical features need to be included in determining the element density distribution. The numerical examples demonstrate the robustness and efficiency of the methodology. Copyright © 2007 John Wiley & Sons, Ltd.
First‐trimester ADAM12 and PAPP‐A as markers for intrauterine fetal growth restriction through their roles in the insulin‐like growth factor system
Authors: Cowans Nicholas J. , Spencer Kevin 
Published: February 2007

AbstractBackgroundPAPP‐A is a marker used as part of the most effective method of screening for chromosomal anomalies in the first trimester. ADAM12 is a recently discovered pregnancy associated member of the ADAM (a multidomain glycoprotein metalloprotease) family. Recently, ADAM12 has been shown as a potential marker for early screening for chromosomal anomalies. Both PAPP‐A and ADAM12 have been identified as proteases to insulin‐like growth factor binding proteins. In this role, they may have a regulatory function in controlling the amount of free bioactive insulin‐like growth factor (IGF). We therefore wish to examine if the levels of either of these proteases are related to various growth related adverse pregnancy outcomes.Materials and MethodsPAPP‐A and ADAM12 were measured in a subset of samples collected at 11 to 14 weeks as part of an OSCAR clinic screening for chromosomal anomalies. Follow‐up of pregnancies screened between September 1999 and August 2003 identified 1705 pregnancies with an outcome of intrauterine fetal demise on or after 24 weeks, preterm delivery at 24–34 weeks or 35–36 weeks, very low birthweight (<1.5 kg), low birthweight (<2.5 kg), large birthweight (>4.5 kg), and birth weight below the 3rd or 5th or 10th centile for gestation. A series of 414 normal outcome pregnancies constituted the control group.Marker levels were adjusted for gestation and maternal weight and the log MoM of the markers were compared using t‐test of unequal variance between the control group and the various adverse outcome groups.ResultsADAM12 and PAPP‐A concentrations were reduced in low for gestational age birth weights and in all births with weights below 2.5 kg. There was a linear relationship between the severity of the IUGR and the decrease in PAPP‐A and ADAM12. In the larger babies, only ADAM12 was found to be significantly increased in babies above the 90th centile of weight for gestation.ConclusionsThe results of our study are compatible with the proposed role of ADAM12 and PAPP‐A in promoting growth and development by breaking down IGF binding proteins and causing the release of free IGF for uptake into cells to promote growth. In those cases that eventually result in poor fetal growth, levels of PAPP‐A and ADAM12 at 11–14 weeks are significantly lower than normal—in this instance, lowered PAPP‐A and ADAM12 would result in less free IGF being available for cell uptake and growth stimulation. Further studies may elucidate if screening using such modalities can lead to new potential treatments for poorly growing fetuses. Copyright © 2007 John Wiley & Sons, Ltd.
Whole genome amplification from a single cell: a new era for preimplantation genetic diagnosis
Authors: Coskun Serdar , Alsmadi Osama 
Published: February 2007

AbstractPreimplantation genetic diagnosis (PGD) is a technique used for determining the genetic status of a single cell biopsied from embryos or oocytes. Genetic analysis from a single cell is both rewarding and challenging, especially in PGD. The starting material is very limited and not replaceable, and the diagnosis has to be made in a very short time. Different whole genome amplification (WGA) techniques have been developed to specifically increase the DNA quantities originating from clinical samples with limited DNA contents. In this review, currently available WGA techniques are introduced and, among them, multiple displacement amplification (MDA) is discussed in detail. MDA generates abundant assay‐ready DNA to perform broad panels of genetic assays through its ability to rapidly amplify genomes from single cells. The utilization of MDA for single‐cell molecular analysis is expanding at a high rate, and MDA is expected to soon become an integral part of PGD. Copyright © 2007 John Wiley & Sons, Ltd.