bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prey–predator size‐dependent functional response: derivation and rescaling to the real world
Authors: Aljetlawi Albashir A. , Sparrevik Erik , Leonardsson Kjell 
Published: March 2004

Summary

We derived a functional response function that accounted for both predator and prey size. Laboratory experiments were then performed to investigate the size relationships of the functional response of the benthic isopod Saduria entomon (L.) feeding on Monoporeia affinis (Lindström) amphipods.
The S. entomon predators, in general, showed sigmoid (type III) functional responses. The attack rate of S. entomon was a bent ridge‐shaped function of predator and prey size. The maximum attack rates of small predators were found on small prey, and then attack rate declined rapidly as prey size increased. In large predators attack rate increased slowly up to a maximum for large prey. The shape of the attack rate was dependent on the size scaling of predator and prey body mass in the attack rate function. We suggest that the ridge‐shaped attack rate function found in our study is likely to be general for predators that feed on prey with a large size range. The handling time of small S. entomon increased rapidly as prey size increased. In contrast, we found only small differences in handling time of large predators. The complete functional response may provide size‐refuges for very small and large M. affinis depending on the size‐structure of S. entomon.
To investigate the realism in our functional response estimates, we incorporated the functional response in a consumption model based on the densities and size‐structures of the predator and the prey in the field (Bothnian Sea). We adjusted the attack rate using a correction factor to predict the observed survival of the different age‐classes of M. affinis from field samples. The field data‐based consumption model accounted for 1 year of size‐dependent predation by the size‐structured population of S. entomon on M. affinis. In addition, using a growth model for S. entomon we checked that the predicted consumption by the predator gave realistic growth curves. We found that the experimentally derived attack rates may have been over‐estimated by a factor of 400.
Clinical response to a vacant post space
Authors: Fishelberg G. 
Published: March 2004

AbstractAim  To report a case demonstrating a radiolucency developing adjacent to an unfilled post space.Summary  A mandibular left first molar was root filled before post‐space preparation. The tooth was restored coronally but the post space was left empty, and 14 months later, pain and furcal radiolucency developed. Cleaning, shaping, medicating and filling the post space resulted in the resolution of symptoms and healing of the radiolucency.Key learning points

Post space should be prepared under conditions of asepsis.
A post space must not be allowed to remain empty when a tooth is restored.
The use of volume expansion in preterm infants
Authors: Tyler W. , Ewer A. K. 
Published: March 2004

SummaryThere is no consensus of opinion regarding the appropriate use of volume expansion in the sick preterm infant. Recent evidence suggests that excessive volume expansion may increase mortality in this group. We determined the use of volume expansion in non‐surgical preterm infants (<30 weeks gestation) among neonatal consultants in the West Midlands. A questionnaire was sent to 40 consultants working in all 16 neonatal units in the West Midlands region and re‐sent one year later after presentation of interim regional mortality data. Responses were received from 15 units in 2000 and all 16 in 2001. Written guidelines for volume expansion were available in only 6 units (38%) in 2000 compared with 15 (94%) in 2001. The maximum volume expansion considered appropriate in the first 36 h of life reduced from a mean 37 mL/kg (range 15–150 mL/kg) in 2000 to 24 mL/kg (range 10–60 mL/kg) in 2001. In 2000 64% limited volume expansion to ≤ 30 mL/kg (compared with 94% in 2001). Following regional discussion of interim mortality data and the subsequent development of unit guidelines, the prescription of volume expansion in the West Midlands region changed, with a reduction in the mean volume considered appropriate and greater consistency between units. The impact on neonatal outcome needs to be determined.
Postnatal risk factors of retinopathy of prematurity
Authors: Kim Tae‐im , Sohn Joonhong , Pi Soo‐young , Yoon Young Hee 
Published: March 2004

SummaryTo investigate the postnatal risk factors of retinopathy of prematurity (ROP), we analysed demographic and clinical data abstracted from the medical records of 425 premature babies who were examined for ROP between January 1994 and December 1998 at Asan Medical Centre, Seoul, Korea. ROP developed in 20.7% of the cases studied. A gestational age (GA) of ≤ 28 weeks and birthweight (BW) of ≤ 1000 g were the most significant risk factors. Ventilator care for ≥ 48 h, apnoea, and use of surfactant independently increased the incidence of ROP. Furthermore, frequent apnoeic attacks increased the progression of pre‐threshold ROP to threshold ROP. Therefore, as well as GA and BW, apnoea, prolonged use of a ventilator, and surfactant therapy are significant independent risk factors for ROP. In addition, apnoea may not only increase the risk of developing ROP, but may also worsen pre‐existing ROP.
A cytosolic glucosyltransferase is required for conversion of starch to sucrose in Arabidopsis leaves at night
Authors: Chia Tansy , Thorneycroft David , Chapple Andrew , Messerli Gaëlle , Chen Jychian , Zeeman Samuel C. , Smith Steven M. , Smith Alison M. 
Published: March 2004

SummaryMaltose is exported from the Arabidopsis chloroplast as the main product of starch degradation at night. To investigate its fate in the cytosol, we characterised plants with mutations in a gene encoding a putative glucanotransferase (disproportionating enzyme; DPE2), a protein similar to the maltase Q (MalQ) gene product involved in maltose metabolism in bacteria. Use of a DPE2 antiserum revealed that the DPE2 protein is cytosolic. Four independent mutant lines lacked this protein and displayed a decreased capacity for both starch synthesis and starch degradation in leaves. They contained exceptionally high levels of maltose, and elevated levels of glucose, fructose and other malto‐oligosaccharides. Sucrose levels were lower than those in wild‐type plants, especially at the start of the dark period. A glucosyltransferase activity, capable of transferring one of the glucosyl units of maltose to glycogen or amylopectin and releasing the other, was identified in leaves of wild‐type plants. Its activity was sufficient to account for the rate of starch degradation. This activity was absent from dpe2 mutant plants. Based on these results, we suggest that DPE2 is an essential component of the pathway from starch to sucrose and cellular metabolism in leaves at night. Its role is probably to metabolise maltose exported from the chloroplast. We propose a pathway for the conversion of starch to sucrose in an Arabidopsis leaf.
Selective and powerful stress gene expression in Arabidopsis in response to malondialdehyde
Authors: Weber Hans , Chételat Aurore , Reymond Philippe , Farmer Edward E. 
Published: March 2004

SummaryThe provenance, half‐life and biological activity of malondialdehyde (MDA) were investigated in Arabidopsis thaliana. We provide genetic confirmation of the hypothesis that MDA originates from fatty acids containing more than two methylene‐linked double bonds, showing that tri‐unsaturated fatty acids are the in vivo source of up to 75% of MDA. The abundance of the combined pool of free and reversibly bound MDA did not change dramatically in stress, although a significant increase in the free MDA pool under oxidative conditions was observed. The half‐life of infiltrated MDA indicated rapid metabolic turnover/sequestration. Exposure of plants to low levels of MDA using a recently developed protocol powerfully upregulated many genes on a cDNA microarray with a bias towards those implicated in abiotic/environmental stress (e.g. ROF1 and XERO2). Remarkably, and in contrast to the activities of other reactive electrophile species (i.e. small vinyl ketones), none of the pathogenesis‐related (PR) genes tested responded to MDA. The use of structural mimics of MDA isomers suggested that the propensity of the molecule to act as a cross‐linking/modifying reagent might contribute to the activation of gene expression. Changes in the concentration/localisation of unbound MDA in vivo could strongly affect stress‐related transcription.
Mutants for photosystem I subunit D of Arabidopsis thaliana: effects on photosynthesis, photosystem I stability and expression of nuclear genes for chloroplast functions
Authors: Ihnatowicz Anna , Pesaresi Paolo , Varotto Claudio , Richly Erik , Schneider Anja , Jahns Peter , Salamini Francesco , Leister Dario 
Published: March 2004

SummaryIn Arabidopsis thaliana, the D‐subunit of photosystem I (PSI‐D) is encoded by two functional genes, PsaD1 and PsaD2, which are highly homologous. Knock‐out alleles for each of the loci have been identified by a combination of forward and reverse genetics. The double mutant psad1‐1 psad2‐1 is seedling‐lethal, high‐chlorophyll‐fluorescent and deficient for all tested PSI subunits, indicating that PSI‐D is essential for photosynthesis. In addition, psad1‐1 psad2‐1 plants show a defect in the accumulation of thylakoid multiprotein complexes other than PSI. Of the single‐gene mutations, psad2 plants behave like wild‐type (WT) plants, whereas psad1‐1 markedly affects the accumulation of PsaD mRNA and protein, and photosynthetic electron flow. Additional effects of the psad1‐1 mutation include a decrease in growth rate under greenhouse conditions and downregulation of the mRNA expression of most genes involved in the light phase of photosynthesis. In the same mutant, a marked decrease in the levels of PSI and PSII polypeptides is evident, as well as a light‐green leaf coloration and increased photosensitivity. Increased dosage of PsaD2 in the psad1‐1 background restores the WT phenotype, indicating that PSI‐D1 and PSI‐D2 have redundant functions.
Tyrosine kinase receptor RON functions downstream of the erythropoietin receptor to induce expansion of erythroid progenitors
Authors: van den Akker Emile , van Dijk Thamar , Parren-van Amelsvoort Martine , Grossmann Katja S. , Schaeper Ute , Toney-Earley Kenya , Waltz Susan E. , Löwenberg Bob , von Lindern Marieke 
Published: March 2004

Abstract
Erythropoietin (EPO) is required for cell survival during differentiation and for progenitor expansion during stress erythropoiesis. Although signaling pathways may couple directly to docking sites on the EPO receptor (EpoR), additional docking molecules expand the signaling platform of the receptor. We studied the roles of the docking molecules Grb2-associated binder-1 (Gab1) and Gab2 in EPO-induced signal transduction and erythropoiesis. Inhibitors of phosphatidylinositide 3-kinase and Src kinases suppressed EPO-dependent phosphorylation of Gab2. In contrast, Gab1 activation depends on recruitment and phosphorylation by the tyrosine kinase receptor RON, with which it is constitutively associated. RON activation induces the phosphorylation of Gab1, mitogen-activated protein kinase (MAPK), and protein kinase B (PKB) but not of signal transducer and activator of transcription 5 (Stat5). RON activation was sufficient to replace EPO in progenitor expansion but not in differentiation. In conclusion, we elucidated a novel mechanism specifically involved in the expansion of erythroblasts involving RON as a downstream target of the EpoR. (Blood. 2004;103:4457-4465)
Facile Conversion of 1-Methyl Group of Guaiazuleue into 1-Formyl Group
Authors: Okajima Toshiya , Kurokawa Shinji 
Published: March 2004

Abstract
1-Formyl-7-isopropyl-4-methylazulene (4) has been synthesized by DDQ oxidation method of 1-methyl group of guaiazulene (1). The overall synthetic procedures from 1 to 4 were completed within 2 h, and almost quantitative yield was achieved. The compound (4) was inaccessible so far, because of a poor yield of 4 in its total synthesis (&lt;5%, overall), as well as in its preparation by non-selective oxidation of 1 (&lt;1%).
Syntheses of Silver Nanofilms, Nanorods, and Nanowires by a Microwave-polyol Method in the Presence of Pt Seeds and Polyvinylpyrrolidone
Authors: Tsuji Masaharu , Nishizawa Yuki , Hashimoto Masayuki , Tsuji Takeshi 
Published: March 2004

Abstract
AgNO3 was reduced by ethylene glycol (EG) in the presence of Pt seeds and polyvinylpyrrolidone (PVP) under microwave heating. In addition to spherical nanoparticles, single-crystalline silver nano-films, rods, and wires were produced. The relative number ratio of nanorods and nanowire to the total silver nanostructures was &lt;14%. The formation mechanism of anisotropic silver nanostructures was discussed.
Deposition of Nanostructured Diamond-like Carbon Films on Al Substrate by Facile Electrochemical Route
Authors: Jiang He-qing , Huang Li-na , Zhang Zhi-jun , Xu Tao , Liu Wei-min 
Published: March 2004

Abstract
Diamond-like carbon (DLC) films were deposited on Al substrate by electrolysis of dimethylsulfoxide (DMSO) at relatively low voltage (150 V). The morphology of the sample was investigated by SEM, indicating that the film was composed of compact grains about 100 nm. The analysis of the films by XPS, FTIR, and Raman spectroscopy revealed that the deposits are typical hydrogenated DLC films.
Two‐dimensional resistivity imaging: a tool in archaeoseismology. An example from ancient Sagalassos (Southwest Turkey)
Authors: Similox‐Tohon Dominique , Vanneste Kris , Sintubin Manuel , Muchez Philippe , Waelkens Marc 
Published: March 2004

AbstractThe ancient Pisidian town of Sagalassos (southwest Turkey) was struck by several earthquakes during Roman and early Byzantine times and was abandoned around the middle of the seventh centuryAD, partly as the result of a devastating earthquake. A nearby epicentre is postulated, although the causative fault has not yet been identified. The identification of such an active fault is, however, important with respect to the assessment of the seismic hazard of the area. Two‐dimensional resistivity imaging has been used to detect the presence of an active normal fault passing underneath Sagalassos, as evidenced by geological, geomorphological and archaeoseismological observations. The resistivity profiles reveal the presence of five stratigraphical layers, i.e. from bottom to top: the bedrock composed of either limestone or ophiolitic me lange, the weathered top of this bedrock, old colluvial material, recent colluvial material that covers archaeological structures and recent scree deposits. The presence of active normal faults is, moreover, indicated by the displacement of the bedrock and the colluvial material on top of it. Offsets of archaeological structures at Sagalassos are likely to be the result of historical reactivations of these faults. The limestone front, overlooking Sagalassos from the north, probably corresponds to the degraded fault plane of the detected fault zone. Sagalassos was thus built on the hanging wall of an active normal fault. Two‐dimensional resistivity imaging proved to be an efficient tool in archaeoseismology. Copyright © 2003 John Wiley & Sons, Ltd.
Ground penetrating radar survey over a Roman building at Groundwell Ridge, Blunsdon St Andrew, Swindon, UK
Authors: Linford N. T. , Linford P. K. 
Published: March 2004

AbstractA ground penetrating Radar (GPR) survey was conducted over well‐preserved building remains revealed during a previous geophysical survey (1996) covering an apparent complex of Roman activity discovered at Groundwell Ridge to the north of Swindon, UK. Despite unfavourable, clay‐rich soil conditions, the GPR survey provided a detailed plan of the Roman remains to a depth of approximately 1 m, confirming their survival in the very near surface. The GPR results complement the previous earth resistance and magnetic surveys and, together, the data suggest the presence of a high status Roman building, possibly incorporating thermoremanent features, for instance associated with a hypocaust system. Copyright © 2004 John Wiley & Sons, Ltd.
Imaging geophysical data—taking the viewer into account
Authors: Dennis T. J. 
Published: March 2004

AbstractA common way of presenting geophysical data from two‐dimensional sources is as a grey‐scale image. Some theoretical background to discrete image representation is described, and the deleterious effects of inappropriate (too sparse) sampling and display of such images discussed in an archaeological context. In high‐quality images, such as magazine illustrations or digital television, the sampling densities can be sufficiently high to avoid the appearance of artefacts. Geophysical images in contrast are often sampled at very low densities; if the effective area of each sample is significantly less than the sample spacing, then the classic effect called ‘aliasing’ in communication engineering, caused by the violation of Nyquist's criterion, will be seen. Knowledge of the sensor's footprint can be used to select an appropriate sample density, and so minimize this source of distortion. To maximize the visibility of what may be low‐contrast structures immersed in a high level of background noise, it is helpful also to consider the bandpass nature of the spatial frequency response of the human visual system. The non‐linear phenomenon of visual masking is shown to influence the choice on presentation methods. Copyright © 2004 John Wiley & Sons, Ltd.
A Simple, Non‐Nucleosidic Base Surrogate Increases the Duplex Stability of DNA Containing an Abasic Site
Authors: Langenegger Simon M. , Häner Robert 
Published: March 2004

AbstractAbasic sites represent a common type of lesion in DNA. If not repaired, they can lead to mutations during replication or to cell death. Due to their biological importance, there is a strong interest in methods of recognizing abasic sites in DNA both for diagnostic and also for potential pharmaceutical applications. Extended aromatic residues can have a substantial positive influence on the stability of double‐stranded DNA containing abasic sites. We report here the use of a simple, non‐nucleosidic phenanthrene as a base surrogate, which effectively enhances the duplex stability of DNA with an abasic site. The influence of the linker length on the stability of the duplex is investigated. Data and model considerations indicate that stabilization is a result of stacking interactions between the phenanthrene and DNA base pairs.
Synthesis and Properties of Oligonucleotides Carrying Cryptolepine Derivatives
Authors: Eritja Ramon 
Published: March 2004

AbstractA carboxy derivative of the antimalarial cytotoxic drug cryptolepine was introduced into synthetic oligonucleotides by reaction of the carboxy derivative of cryptolepine with oligonucleotides carrying an amino group either at the 3′‐ or at the 5′‐end. Oligonucleotides carrying the cryptolepine derivative bind their complementary sequences with greater affinity than unmodified ones. When cryptolepine is attached to a polypyrimidine oligonucleotide designed to form a parallel triplex, the triplex shows none or weak stabilization.
Kinetic Analysis of the Reactions Catalyzed by Histidine and Phenylalanine Ammonia Lyases
Authors: Viergutz Sandra , Rétey János 
Published: March 2004

AbstractAlthough both the structures and the reactions of histidine and phenylalanine ammonia lyases (HAL and PAL) are very similar, the former shows a primary kinetic deuterium (D) isotope effect, while the latter does not. In the HAL reaction, the release of ammonia is partially rate‐determining and is slower than the release of the product (E)‐urocanate (4), whereas in the PAL reaction, the release of (E)‐cinnamate (2) is the rate‐limiting step. With (2S,3S)‐[3‐2H1]phenylalanine (1a), we determined the kinetic D isotope effects with the PAL mutants Q487A, Y350F, L137 H, and the double mutant L137 H/Q487E. The kH/kD values for the former two were of the same magnitude as with wild‐type PAL (1.20±0.07), while the exchange of L137 to H almost doubled the effect (kH/kD=2.32±0.01). We conclude that L137 is part of the hydrophobic pocket harboring the phenyl group of the substrate/product and is responsible for its strong binding. The stability of the HAL ammonia complex was demonstrated 40 years ago. Here, we show that, in contrast to the former assumption, ammonia in the complex is not covalently bound to the prosthetic electrophile, 3,5‐dihydro‐5‐methylidene‐4H‐imidazol‐4‐one (MIO; 5). We carried out experiments with a mutant enzyme lacking MIO and exhibiting ca. 103 times less activity. Nevertheless, the enzymeammonia complex was formed, and the mutant behaved upon addition of (E)‐[14C]urocanate (4a) like wild‐type HAL. We conclude, therefore, that ammonia is bound in the complex by Coulomb forces as ammonium ion and can be released only after (E)‐urocanate (4).
Metapleural‐ and Postpharyngeal‐Gland Secretions from Workers of the Ants Solenopsis invicta and S. geminata
Authors: Cabrera Aivlé , Williams David , Hernández José V. , Caetano Flavio H. , Jaffe Klaus 
Published: March 2004

AbstractChemical analyses by GCMS of the metapleural glands (MG) from workers of Solenopsis invicta and S. geminata revealed for the first time the chemical composition of these glands and showed small differences between the two species. The MG of both species contain oleic, stearic, linoleic, and palmitic acid. Both ants, in addition, have small but significant amounts of hydrocarbons in their MG reservoir, which are the same as those found in their postpharyngeal glands (PPG). The PPG of both species contain alkanes, alkenes, and Me‐branched alkanes. Each species is characterized by a specific composition of PPG chemicals with some overlap between species. These results suggest that the MG synthesizes mainly palmitic, linoleic, oleic, and stearic acids in these two ants, whereas PPG contains hydrocarbon mixes that widely vary between these two phylogenetically related species.
Strain field measurements of rubber by image analysis and design criteria for laminated rubber bearings (LRB)
Authors: Sujeewa Lewangamage Chamindalal , Abe Masato , Fujino Yozo , Yoshida Junji 
Published: March 2004

AbstractAlthough seismic isolation rubber bearings in bridges and buildings have proven to be a very effective passive method for reducing earthquake‐induced forces, a detailed mechanical modeling of the rubber that is used in bearings under large strains has not been established. Therefore, a 3D model of failure behavior and the design criteria for the safety evaluation of seismic isolation bearings have not yet been developed. This paper presents: (1) correlation‐based template‐matching algorithms to measure large strain fields of continua; (2) a failure criterion for rubber; and (3) the design criteria for the safety evaluation of laminated algorithms, data‐validation algorithms were developed and implemented to eliminate possible unrealistic displacement vectors present in the measured displacement field. The algorithms were successfully employed in the strain field measurement of LRB and rubber materials that are subjected to failure. The measured local strains for rubber material at failure were used to develop a failure criterion for rubber. The validity of the proposed criterion was evaluated by applying it to the LRB; the criterion was introduced into a 3D finite element model of LRB, compared with the experimental results of bearings failure, and verified. Finally, design criteria are proposed for LRB for the safety evaluation. Copyright © 2003 John Wiley & Sons, Ltd.