bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modelling and numerical methods for the dynamics of impurities in a gas
Authors: Ferrari E. , Pareschi L. 
Published: November 2007

AbstractThe dynamics of a mixture of impurities in a gas can be represented by a system of linear Boltzmann equations for hard spheres. We assume that the background is in thermodynamic equilibrium and that the polluting particles are sufficiently few (in comparison with the background molecules) to admit that there are no collisions among couples of them. In order to derive non‐trivial hydrodynamic models, we close the Euler system around local Maxwellian's which are not equilibrium states.The kinetic model is solved by using a Monte Carlo method, the hydrodynamic one by implicit–explicit Runge–Kutta schemes with weighted essentially non‐oscillatory reconstruction (J. Sci. Comput. 2005; 25(1–2):129–155). Several numerical tests are then computed in order to compare the results obtained with the kinetic and the hydrodynamic models. Copyright © 2007 John Wiley & Sons, Ltd.
Smiling less at LIFFE
Authors: Lin Bing‐Huei , Chang Ing‐Jye , Paxson Dean A. 
Published: November 2007

AbstractThis study investigates the structure of the implied volatility smile, using the prices of equity options traded on the LIFFE. First, the slope of the implied volatility curve is significantly negative for both individual stocks and index options, and the slope is less negative for longer‐term options. The implied volatility skew can be described by risk‐neutral skewness and kurtosis, with the former having the first‐order effect. Moreover, the implied volatility skew for individual stock options is less severe than for index options. Finally, the relationship between the real and risk‐neutral moments implied in option prices is significant. The results indicate that, for equity options traded on the LIFFE, the slope of the implied volatility skew is flatter than that on the Chicago Board of Exchange (CBOE). © 2008 Wiley Periodicals, Inc. Jrl Fut Mark 28:57–81, 2008
Overweight and obesity and incidence of leukemia: A meta‐analysis of cohort studies
Authors: Larsson Susanna C. , Wolk Alicja 
Published: November 2007

AbstractWe conducted a meta‐analysis to summarize the available evidence from cohort studies on the association between excess body weight and incidence of leukemia. Studies were identified by searching the MEDLINE and EMBASE databases (1966–July 2007) and by examining the references of retrieved articles. A random‐effects model was used to combine the results from individual studies. We identified 9 cohort studies with data on body mass index (BMI) or obesity in relation to incidence of leukemia. Compared with nonoverweight individuals (BMI < 25 kg/m2), the summary relative risks (RRs) of leukemia were 1.14 [95% confidence interval (CI), 1.03–1.25] for overweight individuals (BMI 25–30 kg/m2) and 1.39 (95% CI, 1.25–1.54) for obese (BMI ≥ 30 kg/m2) individuals. On a continuous scale, a 5 kg/m2 increase in BMI was associated with a 13% increased risk of leukemia (RR, 1.13; 95% CI, 1.07–1.19). In a meta‐analysis of 4 studies reporting results on subtypes of leukemia, the summary RRs associated with obesity were 1.25 (95% CI, 1.11–1.41) for chronic lymphocytic leukemia, 1.65 (95% CI, 1.16–2.35) for acute lymphocytic leukemia, 1.52 (95% CI, 1.19–1.95) for acute myeloid leukemia and 1.26 (95% CI, 1.09–1.46) for chronic myeloid leukemia. This meta‐analysis indicates that excess body weight is associated with an increased risk of developing leukemia. © 2007 Wiley‐Liss, Inc.
Transcriptional regulation of human survivin by early growth response (Egr)‐1 transcription factor
Authors: Wagner Mandy , Schmelz Karin , Dörken Bernd , Tamm Ingo 
Published: November 2007

AbstractSurvivin, a member of the inhibitor of apoptosis protein family, is involved in both, inhibition of apoptosis and regulation of cell division. Because of the tumor‐specific expression of survivin, the reduction of its expression is an important therapeutic option in the treatment of malignant diseases. Thus, we analyzed the transcriptional regulation of survivin in order to establish survivin as a target gene for new therapeutic approaches. Here, we describe a novel regulatory region within the survivin promoter. After treatment with phorbol 12‐myristate‐13‐acetate, the early growth response (Egr)‐1 transcription factor binds to the sequence 5′GAGGGGGCG 3′ within the human survivin promoter in vitro and in entire cells. In reporter‐gene assays and overexpression experiments, survivin is downregulated following exogenous expression of wildtype Egr‐1. Using p53 wildtype and mutated cell lines, we show that Egr‐1 negatively regulates survivin expression and sensitizes cell lines to TRAIL‐induced apoptosis. © 2007 Wiley‐Liss, Inc.
Inhibition of telomerase in the endothelial cells disrupts tumor angiogenesis in glioblastoma xenografts
Authors: Falchetti Maria Laura , Mongiardi Maria Patrizia , Fiorenzo Paolo , Petrucci Giovanna , Pierconti Francesco , D'Agnano Igea , D'Alessandris Giorgio , Alessandri Giulio , Gelati Maurizio , Ricci‐Vitiani Lucia , Maira Giulio , Larocca Luigi Maria , Levi Andrea , Pallini Roberto 
Published: November 2007

AbstractTumor angiogenesis is a complex process that involves a series of interactions between tumor cells and endothelial cells (ECs). In vitro, glioblastoma multiforme (GBM) cells are known to induce an increase in proliferation, migration and tube formation by the ECs. We have previously shown that in human GBM specimens the proliferating ECs of the tumor vasculature express the catalytic component of telomerase, hTERT, and that telomerase can be upregulated in human ECs by exposing these cells to GBM in vitro. Here, we developed a controlled in vivo assay of tumor angiogenesis in which primary human umbilical vascular endothelial cells (HUVECs) were subcutaneously grafted with or without human GBM cells in immunocompromised mice as Matrigel implants. We found that primary HUVECs did not survive in Matrigel implants, and that telomerase upregulation had little effect on HUVEC survival. In the presence of GBM cells, however, the grafted HUVECs not only survived in Matrigel implants but developed tubule structures that integrated with murine microvessels. Telomerase upregulation in HUVECs enhanced such effect. More importantly, inhibition of telomerase in HUVECs completely abolished tubule formation and greatly reduced survival of these cells in the tumor xenografts. Our data demonstrate that telomerase upregulation by the ECs is a key requisite for GBM tumor angiogenesis. © 2007 Wiley‐Liss, Inc.
Susceptibility of p27kip1 knockout mice to urinary bladder carcinogenesis induced by N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine may not simply be due to enhanced proliferation
Authors: Hikosaka Atsuya , Ogawa Kumiko , Sugiura Satoshi , Asamoto Makoto , Takeshita Fumitaka , Sato Shin‐Ya , Nakanishi Makoto , Kohri Kenjiro , Shirai Tomoyuki 
Published: November 2007

AbstractDeregulated proliferation is one of the fundamental characteristics of carcinogenesis. p27 is one of the most well characterized negative cell cycle regulator. In our previous study, expression of p27 protein was found to be dramatically suppressed on stimulation of cell proliferation by calculi in the rodent urinary bladder, withdrawal of the insult resulting in re‐expression of p27 and regression of urothelial hyperplastic lesions. In the present study, to evaluate how loss of function impacts on urinary bladder carcinogenesis, N‐butyl‐N‐(4‐hydroxybutyl)nitrosamine (BBN), a bladder carcinogen was given to p27 knockout mice. Males and females with either null, hetero or wild‐type p27 alleles were divided into 2 groups, one given drinking water containing 0.05% BBN for 10 weeks and the other receiving distilled water, then, killed at week 20. The experiment was repeated for confirmation of the outcome. In the second experiment, performed with a larger number of animals, the incidence of urinary bladder carcinomas was significantly higher in female p27‐null mice than in their wild‐type counterparts. p27 deficiency also resulted in their increase of relative weights of urinary bladders and section areas of carcinomas in BBN‐treated mice. Interestingly, while BrdU labeling indices generally increased with progression of mucosal proliferative lesions, from normal epithelium, through hyperplasia to carcinoma, there was no significant variation with the p27 genotype, in tumors as well as normal urothelium. These findings suggest that p27 deficient mice have elevated susceptibility to BBN‐induction of urinary bladder carcinogenesis through a mechanism which might be independent of acceleration of cell cycling. © 2007 Wiley‐Liss, Inc.
Downregulation of XIAP expression in ovarian cancer cells induces cell death in vitro and in vivo
Authors: Shaw Tanya J. , Lacasse Eric C. , Durkin Jon P. , Vanderhyden Barbara C. 
Published: November 2007

AbstractA hallmark of cancer cells is an ability to evade apoptosis. Overexpression and/or activating mutations of prosurvival molecules such as the X‐linked inhibitor of apoptosis (XIAP) contribute to this inappropriate cell survival. Our objectives were to investigate the effects of downregulation of XIAP in ovarian cancer cells in vitro and in vivo using the clinical candidate antisense oligonucleotide against XIAP, AEG35156 (AS XIAP). Three ovarian cancer cell lines were transfected with AS XIAP in vitro, and the effects on cell survival were assessed. Downregulation of XIAP resulted in significant apoptosis. To investigate the in vivo efficacy of AS XIAP, CD‐1 nude mice were xenografted intraperitoneally with A2780‐cp cells, treated with intraperitoneal AS XIAP and evaluated for survival time and tumor histology. Mice treated with 10 mg/kg/day AS XIAP showed a significant improvement in survival time compared to animals treated with control oligonucleotides. Histological analysis of the tumors showed significantly fewer viable cells in the AS XIAP‐treated tumors. Downregulation of XIAP expression in ovarian cancer cells resulted in apoptosis in vitro and a prolonged survival time of ovarian cancer‐bearing mice, which indicate that XIAP may be a valuable therapeutic target in ovarian cancers, and supports the ongoing clinical investigation of AEG35156. © 2007 Wiley‐Liss, Inc.
Influence of temperature and darkness on embryonic diapause termination in dormant Artemia cysts that have never been desiccated
Authors: Nambu Ziro , Tanaka Shin , Nambu Fumiko , Nakano Masahiro 
Published: November 2007

AbstractEnvironmental cues for embryonic diapause termination (EDT) were investigated in the laboratory‐produced encysted dormant embryos of the brine shrimp, Artemia franciscana. The cysts were spawned and kept throughout in a 2% sea salt solution. They were activated by various temperatures of the temperate zones or by continuous dark condition (DD), resulting in a state of EDT, and were thereafter able to resume their subsequent development and hatch under appropriate conditions. The level of EDT was conveniently assayed by a hatch test observed within 2 days at 28°C under continuous light condition (LL). A cold treatment of the newly spawned dormant cysts, at 4°C under DD for more than 100 days, resulted in more than 95% hatch of the dormant cysts. Similar treatments of the dormant cysts but at room temperature or 28°C led to significantly different results (30–40% hatch). Almost all the residual non‐hatched cysts derived from the above could hatch after an additional cold treatment (at 4°C under DD for about 100 days). This might prove to be latent partial bivoltine in Artemia. Meanwhile, a rearing condition (28°C under LL) induced the newly spawned cysts to hatch scatteredly at and after 1 month, resulting in 22% cumulative hatch on the 92nd day after spawning. When the newly spawned dormant cysts were pretreated at 28°C under DD for 5 or 14 days and then reared at 28°C under LL, the cumulative hatch significantly increased (60%). These results are discussed with respect to probable diapause regulator(s) involved in EDT. J. Exp. Zool. 309:17–24, 2008. © 2007 Wiley‐Liss, Inc.
Primary sex ratio in fertilized chicken eggs (Gallus gallus domesticus) depends on reproductive age and selection
Authors: Klein Sabine , Grossmann Roland 
Published: November 2007

AbstractRecent studies of several avian species have shown that the primary sex ratio can change as a result of prevailing conditions, especially in the female bird's first reproductive season. In this study, we sought to determine the primary sex ratio of the first 15 eggs produced in chickens. The study compared chickens which had been commercially selected over many generations for egg‐laying performance (Leghorns) with “fancy‐bred” chickens selected for feather coloration. These fancy‐bred chickens are known to reach reproductive maturity 4 weeks later than Leghorns. A group of precociously matured Leghorn chickens was produced by modification of diet and day length to investigate the effect of age at reproductive maturity on sex ratio. Sex diagnosis was performed on embryos which had died on or before embryonic day 10 by polymerase chain reaction (PCR). Living embryos were allowed to hatch before sex diagnosis. The group of precociously matured White Leghorns reached egg‐laying age 3 weeks earlier than normal. In this group, the sex ratio of hatched chicks was in tendency skewed to females. In the White Leghorns maintained under normal conditions for commercial layers, sex ratio was balanced with a tendency to more males only in the first five eggs. In the group of fancy‐bred chickens, the primary sex ratio was significantly biased toward more males and dependent on the laying sequence. Our data suggested a sex ratio bias toward males in the very first eggs at onset of reproduction in chickens depending on genetic background. J. Exp. Zool. 309:35–46, 2008. © 2007 Wiley‐Liss, Inc.
There exist graphs with super‐exponential Ramsey multiplicity constant
Authors: Fox Jacob 
Published: November 2007

AbstractThe Ramsey multiplicity M(G;n) of a graph G is the minimum number of monochromatic copies of G over all 2‐colorings of the edges of the complete graph Kn. For a graph G with a automorphisms, ν vertices, and E edges, it is natural to define the Ramsey multiplicity constant C(G) to be $\lim_{{n} \to \infty} {M}(G;n){a/v}!{n \choose v}$, which is the limit of the fraction of the total number of copies of G which must be monochromatic in a 2‐coloring of the edges of Kn. In 1980, Burr and Rosta showed that 0 ≥ C(G) ≤ 21−E for all graphs G, and conjectured that this upper bound is tight. Counterexamples of Burr and Rosta's conjecture were first found by Sidorenko and Thomason independently. Later, Clark proved that there are graphs G with E edges and 2E−1C(G) arbitrarily small. We prove that for each positive integer E, there is a graph G with E edges and C(G) ≤ E−E/2 + o(E). © 2007 Wiley Periodicals, Inc. J Graph Theory 57: 89–98, 2008
Phytase–phytate–pectin hypothesis and quality of legumes cooked in calcium solutions
Authors: Galiotou‐Panayotou Maria , Kyriakidis Nikolaos B , Margaris Ioannis 
Published: November 2007

AbstractHard‐to‐cook and easy‐to‐cook bean and lentil seeds were boiled in water containing calcium ions at concentrations of 0, 40, 80, 120 and 160 mg L−1 and their texture and concentration of phytate and various peptic compounds were measured. In order to minimise matrix effects, hard‐to‐cook seeds were prepared from easy‐to‐cook seeds by soaking them at 50 °C. It was found that, as calcium ion concentration increased, phytate concentration decreased and seed hardness increased. Also, during soaking and cooking, phytate and peptic compounds were leached into the water. Losses were larger for hard‐to‐cook seeds than for easy‐to‐cook seeds. These results are consistent with the proposed theory that the formation of hard‐to‐cook legume seeds involves an interaction among divalent cations, phytate and peptic compounds, which is based on the phytase–phytate–pectin hypothesis. Copyright © 2007 Society of Chemical Industry
Simultaneous determination of nine flavonoids and qualitative evaluation of Herba Epimedii by high performance liquid chromatography with ultraviolet detection
Authors: Huang Hao , Liang Mingjin , Zhang Xinmin , Zhang Chuan , Shen Ziyin , Zhang Weidong 
Published: November 2007

AbstractA simple high performance liquid chromatographic method has been developed for the determination of nine flavonoids in Herba Epimedii, including quercetin‐3‐O‐glucoside, epimedin A, hexandraside A, epimedin B, epimedin C, icariin, icariside I, icariside II, and icaritin. The chromatographic separation was performed on a Diamonsil C18 column (5 μm, 250×4.6 mm) with gradient elution by acetonitrile–0.5% acetic buffer (adjusted to pH 5.00 with triethylamine). Methodological validation gave acceptable linearities (r2 >0.9992) and recoveries (ranging from 98.9 to 102.4%). The limits of detection of these flavonoids ranged from 16.3 to 83.3 ng. The results indicated that the contents of flavonoids in Herba Epimedii varied significantly from habitat to habitat with contents ranging from 0.05 to 39.0 mg/g. Twenty five Herba Epimedii samples prepared from five different botanical materials were investigated by the established method, and the results showed the influence of the botanical material and the habitat on the quality of Herba Epimedii. The proposed method is simple, effective, and suitable for the evaluation of this traditional Chinese medicine.
Knowledge management audit in a higher educational institution: a case study
Authors: Biloslavo Roberto , Trnavčevič Anita 
Published: November 2007

AbstractIn the paper, we discuss the available research in the field of knowledge management (KM) from the specific perspective of higher educational (HE) institutions, as organisations comprised of experts. Based on the literature review, we develop a KM audit instrument and apply it to a specific HE institution in order to assess the status of its KM processes. From our study, we can conclude that even if an institution is ‘academic’ in nature and apparently successful, this fact does not necessarily mean that KM processes are institutionalised within the organisation. From this point of view, a HE institution is likely to be subject to the same limitations as any other organisation in the knowledge business. Our paper further gives recommendations to managers of HE institutions on how to assess the effectiveness of KM in their organisations as well as providing information for other researchers who want to conduct a KM audit in similar organisations. Copyright © 2007 John Wiley & Sons, Ltd.
Fabrication and Characterization of Ionic Conducting Nanofibers
Authors: Laforgue Alexis , Robitaille Lucie , Mokrini Asmae , Ajji Abdellah 
Published: November 2007

AbstractThe electrospinning method was used to fabricate nanostructures of Nafion‐poly(vinyl alcohol) (PVA) and Nafion‐poly(ethylene oxide) (PEO). Depending on the ratio between the two polymers, nanospheres and/or nanofibers could be obtained in a reproducible manner. The Nafion‐PVA mats were found to be more conductive than the Nafion‐PEO ones, possibly because of their better mechanical properties when swollen by water. The fiber morphology was always found to be more conductive than the sphere morphology. However, all electrospun mats presented ionic conductivities slightly lower than extruded Nafion 115 or Nafion‐PVA cast films.magnified image
Thermally Stabilized Blue Luminescent Poly(p‐phenylene)s Covered with Polyhedral Oligomeric Silsesquioxanes
Authors: Miyake Junpei , Chujo Yoshiki 
Published: November 2007

AbstractA novel series of poly(p‐phenylene)s (PPPs) with polyhedral oligomeric silsesquioxanes (POSSs) on their side chains was prepared. The obtained POSS‐modified PPPs are as follows: 25POSS‐PPP (2b, containing 25 mol‐% of POSS units in all side chains), 50POSS‐PPP (2c, containing 50 mol‐% of POSS units in all side chains), 100POSS‐PPP (2d, containing 100 mol‐% of POSS units in all side chains), and 0POSS‐PPP (2a, as a blank polymer). Films polymer 2d showed the same absorption and photoluminescence (PL) spectra as those in CHCl3 solution, indicating that bulky POSS units strongly suppressed intermolecular aggregation of the PPP backbone. Polymer 2d showed the same PL spectra even after thermal annealing at 150 °C for 6 h. This enhancement of PL stability is due to the significant effect of the bulky POSS units.magnified image
New Azo Chromophore‐Containing Conjugated Polymers: Facile Synthesis by Using “Click” Chemistry and Enhanced Nonlinear Optical Properties Through the Introduction of Suitable Isolation Groups
Authors: Li Zhong'an , Zeng Qi , Yu Gui , Li Zhen , Ye Cheng , Liu Yunqi , Qin Jingui 
Published: November 2007

AbstractA new series of azobenzene‐containing polyfluorenes have been successfully prepared through polymer reactions by the utilization of “click” chemistry. All the polymers were well characterized and soluble in common solvents. By the application of the concept of “suitable isolation group”, the macroscopic nonlinear optical (NLO) properties of the polymers could be boosted to as large as three times that of the polymer without isolation moieties. Also, all the polymers were thermally stable, and demonstrated good procesability, coupled with improved optical transparency. Thus, they are good candidates for the practical applications as new photonic materials.magnified image
Occurrence of type A trichothecenes in conventionally and organically produced oats and oat products
Authors: Gottschalk Christoph , Barthel Jörg , Engelhardt Gabriele , Bauer Johann , Meyer Karsten 
Published: November 2007

AbstractAmong cereals, oats are known to be very frequently contaminated with type A trichothecenes and so they can play a major role in the exposition of the consumer to these mycotoxins. Seventy representative oat samples of both conventional and organic production were drawn at mills and at wholesale stage according to Commissions Regulation (EC) No 401/2006 and analyzed for nine type A trichothecenes by LC‐MS/MS. High contamination rates were found for most of the toxins in conventional as well as in organic products (e. g. 100% for T‐2 toxin or 99% for HT‐2 toxin). The mean concentration of T‐2/HT‐2 (sum of the toxins) was 17 ± 18 μg/kg (mean ± SD) in all samples, 27 ± 21 μg/kg in conventional, and 7.6 ± 4.6 μg/kg in organic products, respectively. The highest T‐2/HT‐2 level has been determined in conventionally produced oat flakes (85 μg/kg). The mean level of T‐2 tetraol (9.5 ± 7.7 μg/kg) in all samples was found to be even higher than that of T‐2 (5.1 ± 6.0 μg/kg), whereas levels of T‐2 triol, 4,15‐diacetoxyscirpenol, 15‐monoacetoxyscirpenol, and neosolaniol were considerably lower. For oats and oat products from organic farming contamination levels of T‐2, HT‐2, T‐2 triol, T‐2 tetraol, and neosolaniol were significantly lower. The results are discussed with respect to possible health risks for the consumer.