bluuebunny/crossref_metadata_2025_split huggingface dataset:
The preservation potential of microstructures during static grain growth
Authors: Jessell M. W. , Kostenko O. , Jamtveit B. 
Published: June 2003

AbstractGrain growth simulations using the microstructure simulation system Elle have been performed in materials with a pre‐existing grain shape foliation. As might be expected, the foliation is destroyed by the end of the experiment, and grain areas have increased by a factor of seven. The area of material swept by the migrating grain boundaries was monitored, and it was found that at every stage, virtually all of the grains which survived the grain growth process contain one and only one core of ‘unswept’ material. Remarkably these remnant unswept cores preserve a useable record of the initial grain size and the orientation of the grain shape foliation. This work suggests that, even for samples where no equivalent protolith can be found, it may be possible to see past a grain growth episode to estimate the original grain shape and grain size of the rock, and perhaps even reconstruct the grain boundary kinematics. In addition the identification of unswept cores has the potential to help unravel the evolution of grain boundary chemistry in rocks during metamorphism.As an example of a natural system showing these microstructures, we describe a peridotite from Almklovdalen, Norway. This peridotite was infiltrated by aqueous fluids at several stages during late Caledonian exhumation and retrogressive metamorphism. Grain boundary migration associated with the last of these infiltration events swept off abundant intragranular fluid inclusions in the original chlorite‐peridotite. At the grain scale, microstructural mapping of the fluid inclusion rich areas shows that, as with the numerical simulations, many of the grains retain exactly one core of unswept material. Examples of other natural systems discussed include dislocation density distributions and trace element zoning.
Orthopyroxene–sillimanite–quartz assemblages: distribution, petrology, quantitative P–T–X constraints and P–T paths
Authors: Kelsey D. E. , White R. W. , Powell R. 
Published: June 2003

AbstractGranulite facies magnesian metapelites commonly preserve a wide array of mineral assemblages and reaction textures that are useful for deciphering the metamorphic evolution of a terrane. Quantitative pressure, temperature and bulk composition constraints on the development and preservation of characteristic peak granulite facies mineral assemblages such as orthopyroxene + sillimanite + quartz are assessed with reference to calculated phase diagrams. In NCKFMASH and its chemical subsystems, peak assemblages form mainly in high‐variance fields, and most mineral assemblage changes reflect multivariant equilibria. The rarity of orthopyroxene–sillimanite–quartz‐bearing assemblages in granulite facies rocks reflects the need for bulk rock XMg of greater than approximately 0.60–0.65, with pressures and temperatures exceeding c. 8 kbar and 850 °C, respectively. Cordierite coronas mantling peak minerals such as orthopyroxene, sillimanite and quartz have historically been used to infer isothermal decompression P–T paths in ultrahigh‐temperature granulite facies terranes. However, a potentially wide range of P–T paths from a given peak metamorphic condition facilitate retrograde cordierite growth after orthopyroxene + sillimanite + quartz, indicating that an individual mineral reaction texture is unable to uniquely define a P–T vector. Therefore, the interpretation of P–T paths in high‐grade rocks as isothermal decompression or isobaric cooling may be overly simplistic. Integration of quantitative data from different mineral reaction textures in rocks with varying bulk composition will provide the strongest constraints on a P–T path, and in turn on tectonic models derived from these paths.
Daily Sumatriptan for Detoxification From Rebound
Authors: Drucker Peggy , Tepper Stewart 
Published: June 2003

Medications which provide symptomatic relief from headache can transform episodic migraine into chronic daily headache by propagating the daily headache, causing “rebound.” It is possible to restore the episodic migraine pattern by using an inpatient course of intravenous dihydroergotamine.This study was undertaken to explore whether it was possible to use oral sumatriptan in the outpatient setting as a bridge to detoxification for patients with chronic daily headache due to medication overuse. All patients had previously met International Headache Society (IHS) criteria for episodic migraine and currently had greater than 15 days of headache per month for greater than 1 month. These patients were advised to take 25 mg sumatriptan by mouth three times a day for 10 days or until they were headache‐free for 24 hours.Results reveal that of the 26 patients who started the protocol, 58% had reverted to an episodic migraine pattern at 1 month, and 69% were no longer having chronic daily headache at 6 months. This study demonstrates that it is possible to detoxify patients with rebound headaches using oral sumatriptan during the withdrawal period in an outpatient setting.
Pemphigoid gestationis: treatment with immunoapheresis
Authors: Wöhrl Stefan , Geusau Alexandra , Karlhofer Franz , Derfler Kurt , Stingl Georg , Zillikens Detlef 
Published: June 2003

Summary Background: Pemphigoid (herpes) gestationis is a rare blistering disease of pregnancy. Topical and systemic corticosteroids and antihistamines are usually sufficient for treatment. Case report: A patient suffering from severe, therapy‐resistant pemphigoid gestationis was successfully treated with the additional use of six sessions of immunoapheresis. Systemic corticosteroids could be tapered and serum autoantibody levels to bullous pemphigoid antigen 2 (BPAG2 = BP180) significantly dropped during this treatment. Conclusion: Immunoapheresis represents a helpful therapeutic option with few side effects for severe cases of pemphigoid gestationis, unresponsive to conventional treatment.
The Pyruvate decarboxylase1 Gene of Arabidopsis Is Required during Anoxia But Not Other Environmental Stresses
Authors: Kürsteiner Oliver , Dupuis Isabelle , Kuhlemeier Cris 
Published: June 2003

Abstract
Ethanolic fermentation is classically associated with flooding tolerance when plant cells switch from respiration to anaerobic fermentation. However, recent studies have suggested that fermentation also has important functions in the presence of oxygen, mainly in germinating pollen and during abiotic stress. Pyruvate decarboxylase (PDC), which catalyzes the first step in this pathway, is thought to be the main regulatory enzyme. Here, we characterize the PDC gene family in Arabidopsis. PDC is encoded by four closely related genes. By using real-time quantitative polymerase chain reaction, we determined the expression levels of each individual gene in different tissues, under normal growth conditions, and when the plants were subjected to anoxia or other environmental stress conditions. We show that PDC1 is the only gene induced under oxygen limitation among the PDC1 gene family and that a pdc1 null mutant is comprised in anoxia tolerance but not other environmental stresses. We also characterize the expression of the aldehyde dehydrogenase (ALDH) gene family. None of the three genes is induced by anoxia but ALDH2B7 reacts strongly to ABA application and dehydration, suggesting that ALDH may play a role in aerobic detoxification of acetaldehyde. We discuss the possible role of ethanolic fermentation as a robust back-up energy production pathway under adverse conditions when mitochondrial function is disturbed.
Comparative Analysis of the Arabidopsis Pollen Transcriptome
Authors: Honys David , Twell David 
Published: June 2003

AbstractWe present a genome-wide view of the male gametophytic transcriptome in Arabidopsis based on microarray analysis. In comparison with the transcriptome of the sporophyte throughout development, the pollen transcriptome showed reduced complexity and a unique composition. We identified 992 pollen-expressed mRNAs, nearly 40% of which were detected specifically in pollen. Analysis of the functional composition of the pollen transcriptome revealed the over-representation of mRNAs encoding proteins involved in cell wall metabolism, cytoskeleton, and signaling and under-representation of mRNAs involved in transcription and protein synthesis. For several gene families, we observed a common pattern of mutually exclusive gene expression between pollen and sporophytic tissues for different gene family members. Our results provide a 50-fold increase in the knowledge of genes expressed in Arabidopsis pollen. Moreover, we also detail the extensive overlap (61%) of the pollen transcriptome with that of the sporophyte, which provides ample potential to influence sporophytic fitness through gametophytic selection.
Expansion of the Receptor-Like Kinase/Pelle Gene Family and Receptor-Like Proteins in Arabidopsis
Authors: Shiu Shin-Han , Bleecker Anthony B. 
Published: June 2003

Abstract
Receptor-like kinases (RLKs) are a family of transmembrane proteins with versatile N-terminal extracellular domains and C-terminal intracellular kinases. They control a wide range of physiological responses in plants and belong to one of the largest gene families in the Arabidopsis genome with more than 600 members. Interestingly, this gene family constitutes 60% of all kinases in Arabidopsis and accounts for nearly all transmembrane kinases in Arabidopsis. Analysis of four fungal, six metazoan, and two Plasmodium sp. genomes indicates that the family was represented in all but fungal genomes, indicating an ancient origin for the family with a more recent expansion only in the plant lineages. The RLK/Pelle family can be divided into several subfamilies based on three independent criteria: the phylogeny based on kinase domain sequences, the extracellular domain identities, and intron locations and phases. A large number of receptor-like proteins (RLPs) resembling the extracellular domains of RLKs are also found in the Arabidopsis genome. However, not all RLK subfamilies have corresponding RLPs. Several RLK/Pelle subfamilies have undergone differential expansions. More than 33% of the RLK/Pelle members are found in tandem clusters, substantially higher than the genome average. In addition, 470 of the RLK/Pelle family members are located within the segmentally duplicated regions in the Arabidopsis genome and 268 of them have a close relative in the corresponding regions. Therefore, tandem duplications and segmental/whole-genome duplications represent two of the major mechanisms for the expansion of the RLK/Pelle family in Arabidopsis.
Light- and Carbon-Signaling Pathways. Modeling Circuits of Interactions
Authors: Thum Karen E. , Shasha Dennis E. , Lejay Laurence V. , Coruzzi Gloria M. 
Published: June 2003

AbstractHere, we report the systematic exploration and modeling of interactions between light and sugar signaling. The data set analyzed explores the interactions of sugar (sucrose) with distinct light qualities (white, blue, red, and far-red) used at different fluence rates (low or high) in etiolated seedlings and mature green plants. Boolean logic was used to model the effect of these carbon/light interactions on three target genes involved in nitrogen assimilation: asparagine synthetase (ASN1 and ASN2) and glutamine synthetase (GLN2). This analysis enabled us to assess the effects of carbon on light-induced genes (GLN2/ASN2) versus light-repressed genes (ASN1) in this pathway. New interactions between carbon and blue-light signaling were discovered, and further connections between red/far-red light and carbon were modeled. Overall, light was able to override carbon as a major regulator of ASN1 and GLN2 in etiolated seedlings. By contrast, carbon overrides light as the major regulator of GLN2 and ASN2 in light-grown plants. Specific examples include the following: Carbon attenuated the blue-light induction of GLN2 in etiolated seedlings and also attenuated the white-, blue-, and red-light induction of GLN2 and ASN2 in light-grown plants. By contrast, carbon potentiated far-red-light induction of GLN2 and ASN2 in light-grown plants. Depending on the fluence rate of far-red light, carbon either attenuated or potentiated light repression of ASN1 in light-grown plants. These studies indicate the interaction of carbon with blue, red, and far-red-light signaling and set the stage for further investigation into modeling this complex web of interacting pathways using systems biology approaches.
A Conserved 19-Amino Acid Synthetic Peptide from the Carboxy Terminus of Phosphoenolpyruvate Carboxylase Inhibits the in Vitro Phosphorylation of the Enzyme by the Calcium-Independent Phosphoenolpyruvate Carboxylase Kinase
Authors: Alvarez Rosario , García-Mauriño Sofía , Feria Ana-Belén , Vidal Jean , Echevarría Cristina 
Published: June 2003

Abstract
Higher plant phosphoenolpyruvate carboxylase (PEPC) is subject to in vivo phosphorylation of a regulatory serine located in the N-terminal domain of the protein. Studies using synthetic peptide substrates and mutated phosphorylation domain photosynthetic PEPC (C4 PEPC) suggested that the interaction of phosphoenolpyruvate carboxylase kinase (PEPCk) with its target was not restricted to this domain. However, no further information was available as to where PEPCk-C4 PEPC interactions take place. In this work, we have studied the possible interaction of the conserved 19-amino acid C-terminal sequence of sorghum (Sorghum vulgare Pers cv Tamaran) C4 PEPC with PEPCk. In reconstituted assays, a C-terminal synthetic peptide containing this sequence (peptide C19) was found to inhibit the phosphorylation reaction by the partially purified Ca2+-independent PEPCk (50% inhibition of initial activity = 230 μm). This effect was highly specific because peptide C19 did not alter C4 PEPC phosphorylation by either a partially purified sorghum leaf Ca2+-dependent protein kinase or the catalytic subunit of mammalian protein kinase A. In addition, the Ca2+-independent PEPCk was partially but significantly retained in affinity chromatography using a peptide C19 agarose column. Because peptide C15 (peptide C19 lacking the last four amino acids, QNTG) also inhibited C4 PEPC phosphorylation, it was concluded that the amino acid sequence downstream from the QNTG motif was responsible for the inhibitory effect. Specific antibodies raised against peptide C19 revealed that native C4 PEPC could be in two different conformational states. The results are discussed in relation with the reported crystal structure of the bacterial (Escherichia coli) and plant (maize [Zea mays]) enzymes.
The Determinants of Enterprise Risk Management: Evidence From the Appointment of Chief Risk Officers
Authors: Liebenberg André P. , Hoyt Robert E. 
Published: June 2003

AbstractEnterprise risk management (ERM) has captured the attention of risk management professionals and academics worldwide. Unlike the traditional “silo‐based” approach to corporate risk management, ERM enables firms to benefit from an integrated approach to managing risk that shifts the focus of the risk management function from primarily defensive to increasingly offensive and strategic. Despite the heightened interest in ERM, little empirical research has been conducted on the topic. This study provides an initial attempt at identifying the determinants of ERM adoption. We construct a sample of firms that have signaled their use of ERM by appointing a Chief Risk Officer (CRO) who is charged with the responsibility of implementing and managing the ERM program. We use a logistic regression framework to compare these firms to a size‐ and industry‐matched control sample. While our results suggest a general absence of differences in the financial and ownership characteristics of sample and control firms, we find that firms with greater financial leverage are more likely to appoint a CRO. This finding is consistent with the hypothesis that firms appoint CROs to reduce information asymmetry regarding the firm's current and expected risk profile.
Using Industry‐Sponsored Game Nights to Educate About Risk and Insurance
Authors: Hamilton Karen L. , Greene Kelly , Wood David 
Published: June 2003

AbstractAs educators in the field of risk management and insurance, we see know‐ ledge of risk management and insurance as a core business function. However, some colleagues and students see insurance as cold‐call sales or companies with a lot of money that continue to raise their prices. So we have to find ways to make our public aware of the usefulness of risk management and insurance in the business world and in private life and of the opportunities that having such knowledge presents to all business majors and business people. One method that is beginning to show dramatic improvements in at least our students’ perceptions of the field and the major involves industry‐sponsored game nights. While not an academic endeavor nor strictly risk management education, we believe the idea provides a useful tool for opening students’ eyes to the need for knowledge of risk management and insurance and of the opportunities that are available in the insurance industry and its related fields. This article discusses the history of such an event at Appalachian State Univer‐ sity, the current status of the North Carolina Surplus Lines Association (NCSLA) event, and the benefits of the event.
Seeing right through you: Applications of optical imaging to the study of the human brain
Authors: Gratton Gabriele , Fabiani Monica , Elbert Thomas , Rockstroh Brigitte 
Published: June 2003

AbstractA new set of techniques allows for the study of brain function by near‐infrared light, exploiting two optical phenomena: Changes in light absorption are determined by changes in the concentration of substances like oxy‐ and deoxy‐hemoglobin, and changes in light scattering occur as a consequence of variations of properties of membranes and corpuscles in the neural tissue. Methods based on light absorption can be used to study hemodynamic changes in the brain, whereas those based on light scattering can be used to study neuronal activity and to provide anatomical information at a cellular and subcellular level. Three optical imaging approaches can be used to study living tissue: reflection, optical coherence tomography (OCT), and photon migration. These three approaches vary in their penetration (from less than a millimeter for reflection to up to 3–5 cm for photon migration) and spatial resolution (from a micron level for reflection and OCT to a millimeter and centimeter level for photon migration). This issue includes a collection of articles reviewing applications of these technologies to the study of brain and other bodily functions in humans.
Activation of the prefrontal cortex to trauma‐related stimuli measured by near‐infrared spectroscopy in posttraumatic stress disorder due to terrorism
Authors: Matsuo Koji , Kato Tadafumi , Taneichi Kotaro , Matsumoto Akio , Ohtani Toshiyuki , Hamamoto Taku , Yamasue Hidenori , Sakano Yuji , Sasaki Tsukasa , Sadamatsu Miyuki , Iwanami Akira , Asukai Nozomi , Kato Nobumasa 
Published: June 2003

AbstractTo develop a noninvasive method for psychophysiological assessment of posttraumatic stress disorder (PTSD), 34 victims of the Tokyo Subway Sarin Attack in 1995 including 8 diagnosed as PTSD and 12 controls were examined by a multichannel near‐infrared spectroscopy (NIRS) system. Hemodynamic response in the prefrontal cortex was monitored during the presentation of trauma‐related and control stimuli by video images. Skin conductance response (SCR) was also examined. Oxygenated hemoglobin significantly increased during the trauma‐related image in the victims with or without PTSD. Deoxygenated hemoglobin significantly decreased only in victims with PTSD. No significant alteration was found in controls. Significantly enhanced SCR was also observed in the victims with PTSD during trauma‐related stimuli. The findings suggest that measurement of cerebral hemodynamic response by NIRS is useful for psychophysiological assessment of PTSD.
Fast cerebral functional signal in the 100‐ms range detected in the visual cortex by frequency‐domain near‐infrared spectrophotometry
Authors: Wolf Martin , Wolf Ursula , Choi Jee H. , Toronov Vladislav , Adelina Paunescu L. , Michalos Antonios , Gratton Enrico 
Published: June 2003

AbstractBrain activity is associated with physiological changes, which alter the optical properties of the tissue in the near‐infrared part of the spectrum. Two major types of optical signals following functional brain activation can be distinguished: a slow signal due to hemodynamic changes and a fast signal, which is directly related to neuronal activity. The fast signal is small and therefore difficult to detect. We used a specially noise‐optimized frequency‐domain near‐infrared spectrometer with a π‐sensor, which was expected to be particularly sensitive to deeper tissue layers, to investigate the human visual cortex during visual stimulation generated by a checkerboard. We were able to detect significant fast signals in single light bundles, but not in π‐signals. The fast signals were mostly collocated with strong slow hemodynamic signals, but showed a higher degree of localization than the latter. The latencies of 40±16 ms of the fast signals were similar between locations. Our results also indicate that the brain responds differently to a single and double (forth and back) reversal of the checkerboard, with a stronger reaction upon the double reversal.
The event‐related optical signal (EROS) in visual cortex: Replicability, consistency, localization, and resolution
Authors: Gratton Gabriele , Fabiani Monica 
Published: June 2003

AbstractWe previously reported a fast and localized noninvasive event‐related optical signal (EROS) elicited by visual field quadrant stimulation in occipital brain areas (Gratton, Corballis, Cho, Fabiani, & Hood, 1995). We now present a replication and extension of that experiment. In addition, we propose a new method for estimating the cross‐validity of the results based on intersubject correlations, report further data on the localization of EROS, and present an analysis of its spatial resolution. The results replicate our original findings. The intersubject correlation is generally quite high (r=.6–.8). The spatial resolution analysis indicates that activities from cortical areas located approximately 1.5 cm apart are measurable independently without cross talk. This study provides further support for the idea that noninvasive optical imaging can be used to derive images of brain activity combining good spatial and temporal resolution.
A generally robust approach to hypothesis testing in independent and correlated groups designs
Authors: Keselman H. J. , Wilcox Rand R. , LIX Lisa M. 
Published: June 2003

AbstractStandard least squares analysis of variance methods suffer from poor power under arbitrarily small departures from normality and fail to control the probability of a Type I error when standard assumptions are violated. These problems are vastly reduced when using a robust measure of location; incorporating bootstrap methods can result in additional benefits. This paper illustrates the use of trimmed means with an approximate degrees of freedom heteroskedastic statistic for independent and correlated groups designs in order to achieve robustness to the biasing effects of nonnormality and variance heterogeneity. As well, we indicate when a boostrap methodology can be effectively employed to provide improved Type I error control. We also illustrate, with examples from the psychophysiological literature, the use of a new computer program to obtain numerical results for these solutions.