bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surfactant‐mediated matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry of small molecules
Authors: Grant David C. , Helleur Robert J. 
Published: February 2007

AbstractA variety of surfactants have been tested as matrix‐ion suppressors for the analysis of small molecules by matrix‐assisted laser desorption/ionization time‐of flight mass spectrometry. Their addition to the common matrix α‐cyano‐4‐hydroxycinnamic acid (CHCA) greatly reduces the presence of matrix‐related ions when added at the appropriate mole ratio of CHCA/surfactant, while still allowing the analyte signal to be observed. A range of cationic quaternary ammonium surfactants, as well as a neutral and anionic surfactant, was tested for the analysis of phenolics, phenolic acids, peptides and caffeine. It was found that the cationic surfactants, particularly cetyltrimethylammonium bromide (CTAB), were suitable for the analysis of acidic analytes. The anionic surfactant, sodium dodecyl sulfate, showed promise for peptide analysis. For trialanine, the detection limit was observed to be in the 100 femtomole range. The final matrix/surfactant mole ratio was a critical parameter for matrix ion suppression and resulting intensity of analyte signal. It was also found that the mass resolution of analytes was improved by 25–75%. Depth profiling of sample spots, by varying the number of laser shots, revealed that the surfactants tend to migrate toward the top of the droplet during crystallization, and that it is likely that the analyte is also enriched in this surface region. Here, higher analyte/surfactant concentration would reduce matrix‐matrix interactions (known to be a source of matrix‐derived ions). Copyright © 2007 John Wiley & Sons, Ltd.
Toxicity of copper in butterfish (Poronotus triacanthus): Tissues accumulation and ultrastructural changes
Authors: Jiraungkoorskul Wannee , Sahaphong Somphong , Kangwanrangsan Niwat 
Published: February 2007

AbstractThe present study investigated the accumulation of copper in various tissues and ultrastructural alterations in butterfish, Poronotus triacanthus. In acute toxicity test, butterfish were exposed to 250 μg/L copper for 24 h. In subacute toxicity test, fish were exposed to 25 μg/L copper for 7 days and then returned to normal water for 48 h. The levels of copper accumulation in the tissues were determined by using an atomic absorption spectrometer. After the 7 day exposure, the highest level of copper was found in the liver, followed by kidney, gills, and muscle tissues (3.64, 0.62, 0.59, and 0.34 μg/L, respectively). The recovery group has shown some reduction in copper level in these tissues when compared with those of the 7 day exposure group (3.09, 0.34, 0.30, and 0.27 μg/L, respectively). In gills, the major changes such as filament cell proliferation, increase in intercellular spaces, epithelial lifting, and thickening of the filament and lamellar epithelium were observed. In liver, the major changes such as swollen mitochondria, fragmented in rough endoplasmic reticulum, increases in number and size of lysosomes and lipid droplets. Infiltration of leukocytes, increasing hepatocyte size with pyknotic nuclei, and presence of vacuoles were also observed. In kidney, the changes included alterations of the first proximal tubules, as well as vacuolization of the cytoplasm, proliferation of lysosomes and mitochondria, dilation of endoplasmic reticulum, and finally, cell necrosis. The transmission electron microscopic analysis revealed that the 7 day exposure group had more severe effect in tissue alterations than the 24 h exposure group. Tissue regeneration was also observed in the 48 h recovery group. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 92–100, 2007.
Photodynamic therapy against cyanobacteria
Authors: Drábková M. , Maršálek B. , Admiraal W. 
Published: February 2007

AbstractThis study explores the use of photosensitizers and reactive oxygen species (ROS) to limit growth of cyanobacteria. We chose 12 phthalocyanines, tetraphenol porphyrine, and methylene blue as compounds producing singlet oxygen. Hydrogen peroxide was chosen as another source of ROS. These compounds were tested using algal toxicity tests in microplates on three cultures of green algae (Pseudokirchneriella subcapitata, Scenedesmus quadricauda, and Chlorella kessleri) and on three cultures of cyanobacteria (Synechococcus nidulans, Microcystis incerta, and Anabaena sp.). Results indicate that photosensitizers and singlet oxygen could be highly toxic for some selected phytoplankton species. Green alga Scenedesmus quadricauda was highly sensitive (EC50 = 0.07 mg/L) to compounds producing singlet oxygen, although it was not sensitive to hydrogen peroxide, which was about 10 times more toxic for cyanobacteria. We conclude that the compounds producing hydroxyl radical species seems to be more promising to treat cyanobacterial blooms than the compounds producing the singlet oxygen. © 2007 Wiley Periodicals, Inc. Environ Toxicol 22: 112–115, 2007.
Equations of motion for a rotor blade, including gravity, pitch action and rotor speed variations
Authors: Kallesøe B. S. 
Published: February 2007

AbstractThis paper extends Hodges–Dowell's partial differential equations of blade motion, by including the effects from gravity, pitch action and varying rotor speed. New equations describing the pitch action and rotor speeds are also derived. The physical interpretation of the individual terms in the equations is discussed. The partial differential equations of motion are approximated by ordinary differential equations of motion using an assumed mode method. The ordinary differential equations are used to simulate a sudden pitch change of a rotating blade. This work is a part of a project on pitch blade interaction, and the model will be extended to include an aerodynamic model and be used for analysis of basic properties of pitch blade interaction. Copyright © 2007 John Wiley & Sons, Ltd.
Effects of forest‐floor avalanche disturbance on the structure and dynamics of a subalpine forest near the forest limit on Mt. Fuji
Authors: Tanaka Atsushi , Yamamura Yasuo , Nakano Takashi 
Published: February 2007

AbstractIn subalpine forests near the forest limit on Mt. Fuji in central Japan, slush avalanches occasionally destroy forest‐floor vegetation through an influx of volcanic gravel from bare upper sites. The vegetation structure of Larix kaempferi–Abies veitchii forests near and distant from avalanche paths was investigated to determine the effects of forest‐floor disturbance on successional processes. The Larix population in a forest near an avalanche path, where there had been signs of forest‐floor disturbance by avalanches, had a discontinuous age structure with three age groups, indicating that Larix seedlings established under the Larix canopy after the forest‐floor disturbance. In contrast, the Larix population in a forest distant from avalanche paths, where there had been no forest‐floor disturbance, had a continuous age structure, with no plants younger than the 90‐year‐old trees, indicating that this population had established on bare ground over a long period. These data suggest that the primary requirement for the regeneration of L. kaempferi on the forest floor is a mineral substrate. Conversely, A. veitchii had a continuous age structure in both forests. However, forest‐floor disturbances by avalanche(s) may exclude A. veitchii from the forest because A. veitchii is very sensitive to scoria deposition. In conclusion, forest‐floor disturbance by avalanche(s) provides L. kaempferi with an opportunity to establish on the forest floor, resulting in the maintenance of Larix forests alongside avalanche paths in the upper subalpine area on Mt. Fuji.
Mesenchymal cells from human amniotic fluid survive and migrate after transplantation into adult rat brain
Authors: Cipriani Sabrina , Bonini Daniela , Marchina Eleonora , Balgkouranidou Ioanna , Caimi Luigi , Zucconi Gigliola Grassi , Barlati Sergio 
Published: February 2007

AbstractAmniotic fluid has been recently suggested as an alternative source of mesenchymal stem cells. However, the fate of amniotic fluid‐derived mesenchymal stem cells (AF‐MSCs) after in vivo transplantation has yet to be determined. In the present study we explored whether human AF‐MSCs could survive and migrate following transplantation into the striatum of normal and ischemic rat. We found that the grafted cells could survive and migrate towards multiple brain regions in the normal animals, while they moved towards the injured region in the ischemic rat. Double‐immunostaining analyses showed that the implanted human AF‐MSCs express markers for immature neurons (Doublecortin) at 10 days, and for astrocytes (GFAP) at 10, 30 and 90 after transplantation. This study provides the first evidence that human amniotic fluid contains cells having the potential to survive and integrate into adult rat brain tissue and, therefore, to function as effective stem cells for therapeutic strategies.
Modulatory effects of luteolin on osteoblastic function and inflammatory mediators in osteoblastic MC3T3‐E1 cells
Authors: Choi Eun‐Mi 
Published: February 2007

AbstractThe effects of luteolin on the function of osteoblastic MC3T3‐E1 cells and the production of local factors in osteoblasts were investigated. Luteolin (1 μM) caused a significant elevation of collagen content, alkaline phosphatase (ALP) activity, and osteocalcin secretion in the cells (P< 0.05). The effect of luteolin in increasing collagen content and ALP activity was completely prevented by the presence of 10−6M cycloheximide and 10−6M tamoxifen, suggesting that luteolin's effect results from a newly synthesized protein component and might be partly involved in estrogen action. We then examined the effect of luteolin on the 3‐morpholinosydnonimine (SIN‐1)‐induced production of oxidative stress markers [nitric oxide (NO) and prostaglan E2(PGE2)] and cytokines [tumor necrosis factor‐α (TNF‐α) and interleukin‐6 (IL‐6)] in osteoblasts. Luteolin (1 and 10 μM) decreased the SIN‐1‐induced production of NO, PGE2, TNF‐α, and IL‐6 in osteoblasts. These results suggest that inflammatory mediators can be regulated by luteolin stimulating osteoblastic function.
A pair of non-homeomorphic product measures on the Cantor set
Authors: AUSTIN TIM D. 
Published: February 2007

AbstractFor r ∈ [0, 1] let μr be the Bernoulli measure on the Cantor set given as the infinite power of the measure on {0, 1} with weights r and 1 − r. For r, s ∈ [0, 1] it is known that the measure μr is continuously reducible to μs (that is, there is a continuous map sending μr to μs) if and only if s can be written as a certain kind of polynomial in r; in this case s is said to be binomially reducible to r. In this paper we answer in the negative the following question posed by Mauldin:Is it true that the product measures μrand μsare homeomorphic if and only if each is a continuous image of the other, or, equivalently, each of the numbersrandsis binomially reducible to the other?
Comparisons between bupropion and dexamphetamine in a range of in vivo tests exploring dopaminergic transmission
Authors: Bredeloux P , Dubuc I , Costentin J 
Published: February 2007

Background and purpose:In the present study we investigated, in a range of in vivo tests whether the antidepressant bupropion, and its metabolites shared the dopamine releasing effect of the chemically related dexamphetamine.Experimental approach:We compared bupropion and dexamphetamine in different neurochemical (microdialysis, DOPAC and HVA contents) and behavioural tests, assessing their effects in animals pretreated with a variety of agents (reserpine, sodium hydroxy‐4‐butyrate or haloperidol) known to modify dopaminergic transmission.Key results:In mice, dexamphetamine, like bupropion, increased at low doses and reduced at high doses, locomotor activity. Dexamphetamine restored the locomotor activity in mice made akinetic by either sodium hydroxy‐4‐butyrate or reserpine, whereas bupropion did not. Moreover, bupropion prevented the dexamphetamine‐induced reversal of akinetic effects of reserpine. Haloperidol abolished the locomotor‐stimulant effects of dexamphetamine but did not suppress stimulation by bupropion. In microdialysis experiments, in chloral hydrate anesthetized rats, low doses of dexamphetamine (1 mg kg−1) markedly increased the extracellular dopamine concentration in striatum (340%), while bupropion (100 mg kg−1) produced only a moderate increase (150%). Finally, in rat striatum, as well as in the nucleus accumbens, bupropion increased the effect of haloperidol on DOPAC and HVA concentrations, whereas dexamphetamine reduced these haloperidol effects.Conclusions and implications:Considering only dopaminergic transmission, our results demonstrated that bupropion and metabolites displayed in vivo, as did bupropion in vitro, an inhibition of dopamine uptake and, contrast to dexamphetamine, were devoid of dopamine releasing effects.British Journal of Pharmacology (2007) 150, 711–719. doi:10.1038/sj.bjp.0707151
Cultural Differences in Brand Extension Evaluation: The Influence of Analytic versus Holistic Thinking
Authors: Monga Alokparna Basu , John Deborah Roedder 
Published: February 2007

Abstract
Consumers evaluate brand extensions by judging how well they fit with the parent brand. We examine this process across cultures. We predict that consumers from Eastern cultures, characterized by holistic thinking, perceive higher brand extension fit and evaluate brand extensions more favorably than do Western consumers, characterized by analytic thinking. Study 1 supports the existence of these cultural differences, with study 2 providing support for styles of thinking (analytic vs. holistic) as the drivers of cultural differences in brand extension evaluations.
F-Box Proteins in Rice. Genome-Wide Analysis, Classification, Temporal and Spatial Gene Expression during Panicle and Seed Development, and Regulation by Light and Abiotic Stress
Authors: Jain Mukesh , Nijhawan Aashima , Arora Rita , Agarwal Pinky , Ray Swatismita , Sharma Pooja , Kapoor Sanjay , Tyagi Akhilesh K. , Khurana Jitendra P. 
Published: February 2007

AbstractF-box proteins constitute a large family in eukaryotes and are characterized by a conserved F-box motif (approximately 40 amino acids). As components of the Skp1p-cullin-F-box complex, F-box proteins are critical for the controlled degradation of cellular proteins. We have identified 687 potential F-box proteins in rice (Oryza sativa), the model monocotyledonous plant, by a reiterative database search. Computational analysis revealed the presence of several other functional domains, including leucine-rich repeats, kelch repeats, F-box associated domain, domain of unknown function, and tubby domain in F-box proteins. Based upon their domain composition, they have been classified into 10 subfamilies. Several putative novel conserved motifs have been identified in F-box proteins, which do not contain any other known functional domain. An analysis of a complete set of F-box proteins in rice is presented, including classification, chromosomal location, conserved motifs, and phylogenetic relationship. It appears that the expansion of F-box family in rice, in large part, might have occurred due to localized gene duplications. Furthermore, comprehensive digital expression analysis of F-box protein-encoding genes has been complemented with microarray analysis. The results reveal specific and/or overlapping expression of rice F-box protein-encoding genes during floral transition as well as panicle and seed development. At least 43 F-box protein-encoding genes have been found to be differentially expressed in rice seedlings subjected to different abiotic stress conditions. The expression of several F-box protein-encoding genes is also influenced by light. The structure and function of F-box proteins in plants is discussed in light of these results and the published information. These data will be useful for prioritization of F-box proteins for functional validation in rice.
Comprehensive Screening of Arabidopsis Mutants Suggests the Lysine Histidine Transporter 1 to Be Involved in Plant Uptake of Amino Acids
Authors: Svennerstam Henrik , Ganeteg Ulrika , Bellini Catherine , Näsholm Torgny 
Published: February 2007

Abstract
Plant nitrogen (N) uptake is a key process in the global N cycle and is usually considered a “bottleneck” for biomass production in land ecosystems. Earlier, mineral N was considered the only form available to plants. Recent studies have questioned this dogma and shown that plants may access organic N sources such as amino acids. The actual mechanism enabling plants to access amino acid N is still unknown. However, a recent study suggested the Lysine Histidine Transporter 1 (LHT1) to be involved in root amino acid uptake. In this study, we isolated mutants defective in root amino acid uptake by screening Arabidopsis (Arabidopsis thaliana) seeds from ethyl methanesulfonate-treated plants and seeds from amino acid transporter T-DNA knockout mutants for resistance against the toxic d-enantiomer of alanine (Ala). Both ethyl methanesulfonate and T-DNA knockout plants identified as d-Ala resistant were found to be mutated in the LHT1 gene. LHT1 mutants displayed impaired capacity for uptake of a range of amino acids from solutions, displayed impaired growth when N was supplied in organic forms, and acquired substantially lower amounts of amino acids than wild-type plants from solid growth media. LHT1 mutants grown on mineral N did not display a phenotype until at the stage of flowering, when premature senescence of old leaf pairs occurred, suggesting that LHT1 may fulfill an important function at this developmental stage. Based on the broad and unbiased screening of mutants resistant to d-Ala, we suggest that LHT1 is an important mediator of root uptake of amino acids. This provides a molecular background for plant acquisition of organic N from the soil.
The MtMMPL1 Early Nodulin Is a Novel Member of the Matrix Metalloendoproteinase Family with a Role in Medicago truncatula Infection by Sinorhizobium meliloti
Authors: Combier Jean-Philippe , Vernié Tatiana , de Billy Françoise , El Yahyaoui Fikri , Mathis René , Gamas Pascal 
Published: February 2007

Abstract
We show here that MtMMPL1, a Medicago truncatula nodulin gene previously identified by transcriptomics, represents a novel and specific marker for root and nodule infection by Sinorhizobium meliloti. This was established by determining the spatial pattern of MtMMPL1 expression and evaluating gene activation in the context of various plant and bacterial symbiotic mutant interactions. The MtMMPL1 protein is the first nodulin shown to belong to the large matrix metalloendoproteinase (MMP) family. While plant MMPs are poorly documented, they are well characterized in animals as playing a key role in a number of normal and pathological processes involving the remodeling of the extracellular matrix. MtMMPL1 represents a novel MMP variant, with a substitution of a key amino acid residue within the predicted active site, found exclusively in expressed sequence tags corresponding to legume MMP homologs. An RNA interference approach revealed that decreasing MtMMPL1 expression leads to an accumulation of rhizobia within infection threads, whose diameter is often significantly enlarged. Conversely, MtMMPL1 ectopic overexpression under the control of a constitutive (35S) promoter led to numerous abortive infections and an overall decrease in the number of nodules. We discuss possible roles of MtMMPL1 during Rhizobium infection.
Overexpression of an R1R2R3 MYB Gene, OsMYB3R-2, Increases Tolerance to Freezing, Drought, and Salt Stress in Transgenic Arabidopsis
Authors: Dai Xiaoyan , Xu Yunyuan , Ma Qibin , Xu Wenying , Wang Tai , Xue Yongbiao , Chong Kang 
Published: February 2007

Abstract
We used a cDNA microarray approach to monitor the expression profile of rice (Oryza sativa) under cold stress and identified 328 cold-regulated genes. Thirteen such genes encoding MYB, homeodomain, and zinc finger proteins with unknown functions showed a significant change in expression under 72-h cold stress. Among them, OsMYB3R-2 was selected for further study. Unlike most plant R2R3 MYB transcription factors, OsMYB3R-2 has three imperfect repeats in the DNA-binding domain, the same as in animal c-MYB proteins. Expression of OsMYB3R-2 was induced by cold, drought, and salt stress. The Arabidopsis (Arabidopsis thaliana) transgenic plants overexpressing OsMYB3R-2 showed increased tolerance to cold, drought, and salt stress, and the seed germination of transgenic plants was more tolerant to abscisic acid or NaCl than that of wild type. The expression of some clod-related genes, such as dehydration-responsive element-binding protein 2A, COR15a, and RCI2A, was increased to a higher level in OsMYB3R-2-overexpressing plants than in wild type. These results suggest that OsMYB3R-2 acts as a master switch in stress tolerance.
Specific Roles of α- and γ-Tocopherol in Abiotic Stress Responses of Transgenic Tobacco
Authors: Abbasi Ali-Reza , Hajirezaei Mohamad , Hofius Daniel , Sonnewald Uwe , Voll Lars M. 
Published: February 2007

Abstract
Tocopherols are lipophilic antioxidants that are synthesized exclusively in photosynthetic organisms. In most higher plants, α- and γ-tocopherol are predominant with their ratio being under spatial and temporal control. While α-tocopherol accumulates predominantly in photosynthetic tissue, seeds are rich in γ-tocopherol. To date, little is known about the specific roles of α- and γ-tocopherol in different plant tissues. To study the impact of tocopherol composition and content on stress tolerance, transgenic tobacco (Nicotiana tabacum) plants constitutively silenced for homogentisate phytyltransferase (HPT) and γ-tocopherol methyltransferase (γ-TMT) activity were created. Silencing of HPT lead to an up to 98% reduction of total tocopherol accumulation compared to wild type. Knockdown of γ-TMT resulted in an up to 95% reduction of α-tocopherol in leaves of the transgenics, which was almost quantitatively compensated for by an increase in γ-tocopherol. The response of HPT and γ-TMT transgenics to salt and sorbitol stress and methyl viologen treatments in comparison to wild type was studied. Each stress condition imposes oxidative stress along with additional challenges like perturbing ion homeostasis, desiccation, or disturbing photochemistry, respectively. Decreased total tocopherol content increased the sensitivity of HPT:RNAi transgenics toward all tested stress conditions, whereas γ-TMT-silenced plants showed an improved performance when challenged with sorbitol or methyl viologen. However, salt tolerance of γ-TMT transgenics was strongly decreased. Membrane damage in γ-TMT transgenic plants was reduced after sorbitol and methyl viologen-mediated stress, as evident by less lipid peroxidation and/or electrolyte leakage. Therefore, our results suggest specific roles for α- and γ-tocopherol in vivo.