bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical studies on the mechanism of formation of a heteropolycyclic germanic compound between dimethyl‐germylidene and ethylene
Authors: Tian Chun Liang , Xu Yue Hua , Lu Xiu Hui
Published: June 2009

Mechanism of the cycloadditional reaction between singlet dimethyl‐germylidene (R1) and ethylene (R2) has been investigated with MP2/6‐31G* method, including geometry optimization and vibrational analysis for the involved stationary points on the potential energy surface. The energies of the different conformations are calculated by CCSD(T)//MP2/6‐31G* method. From the potential energy profile, it can be predicted that the dominant reaction pathway of the cycloadditional reaction of forming a heteropolycyclic germanic compound between singlet dimethyl‐germylidene and ethylene consists of three steps: (1) the two reactants (R1, R2) first form a three‐membered intermediate (INT1) through a barrier‐free exothermic reaction of 39.6 kJ/mol. (2) Three‐membered intermediate (INT1) isomerizes to an active four‐membered intermediate (INT2) via a transition state (TS2), for which the barrier is 50.1 kJ/mol. (3) Four‐membered intermediate (INT2) reacts further with ethylene (R2) to form a heteropolycyclic germanic compound (P3), which is also a barrier‐free exothermic reaction of 87.7 kJ/mol. This dominant reaction has an excellent selectivity and differs considerably from its competitive reactions in thermodynamic property and reaction rate. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Rapid separation and identification of furocoumarins in Angelica dahurica by high‐performance liquid chromatography with diode‐array detection, time‐of‐flight mass spectrometry and quadrupole ion trap mass spectrometry
Authors: Zhang Hai , Gong Chungui , Lv Lei , Xu Yuanjie , Zhao Liang , Zhu Zhenyu , Chai Yifeng , Zhang Guoqing
Published: June 2009

High‐performance liquid chromatography with diode‐array detection (HPLC/DAD), time‐of‐flight mass spectrometry (HPLC/TOFMS) and quadrupole ion trap mass spectrometry (HPLC/QITMS) were used for separation, identification and structural analysis of furocoumarins in Angelica dahurica. Two furocoumarins (imperatorin and isoimperatorin) in Angelica dahurica extract were identified unambiguously by comparing their relative retention times, characteristic ultraviolet information and accurate mass measurement. A formula database of known furocoumarins in Angelica dahurica was established, against which the other 21 furocoumarins were identified effectively based on the accurate extract masses and formulae acquired by HPLC/TOFMS. In order to distinguish the isomers, multi‐stage mass spectrometry (MSn, ion trap mass spectrometry) was used. General fragmentation behavior of the furocoumarins in the ion trap mass spectrometer was studied by the two furocoumarin standards, and their fragmentation rules in MSn spectra were summarized. These deduced fragmentation rules of furocoumarins were successfully implemented in distinguishing the three groups of isomers in Angelica dahurica by HPLC/QITMS. By using the three different analytical techniques, 23 furocoumarins in Angelica dahurica were tentatively identified within 30 min. Finally, HPLC/TOFMS fingerprints of Angelica dahurica were established by which it can be concluded that a rapid and effective method based on the three analytical techniques for identification of chemical components was established. This can provide help for further quality control of Angelica dahurica and pharmacology mechanism study of furocoumarins in Angelica dahurica. Copyright © 2009 John Wiley & Sons, Ltd.
High‐temperature mass spectrometric study of the vaporization processes in the system CaO‐MgO‐Al2O3‐Cr2O3‐FeO‐SiO2
Authors: Wang L. J. , Stolyarova V. L. , Lopatin S. I. , Seetharaman S.
Published: June 2009

Knudsen effusion mass spectrometry was used to study vaporization processes and thermodynamic properties of twenty samples of chromium‐containing slags in the CaO‐MgO‐Al2O3‐Cr2O3‐FeO‐SiO2 system in the temperature range 1850–2750 K. Tungsten cells were used and Cr2O3 solid was used as a reference material. The system was calibrated using liquid gold. As FeO was the first emanating vapor species, monitoring of the chromium‐containing species could be carried out only after the complete vaporization of FeO. This, however, was found to have very little impact on the concentration of the slags investigated. During the measurements, the ion current intensities of CrO+ and CrO species in the mass spectra of the vapor over the CaO‐MgO‐Al2O3‐Cr2O3‐FeO‐SiO2 samples were monitored and compared with those corresponding to solid Cr2O3. Data on the partial pressures of vapor species as well as the activities of Cr2O3 as a function of temperature were obtained. The results are expected to be valuable in the optimization of slag composition in high alloy steelmaking processes. Copyright © 2009 John Wiley & Sons, Ltd.
Probing the limits of liquid droplet laser desorption mass spectrometry in the analysis of oligonucleotides and nucleic acids
Authors: Hoffmann Jan , Schmidt Thorsten. L. , Heckel Alexander , Brutschy Bernd
Published: June 2009

In the present work we demonstrate the advantages of LILBID mass spectrometry (laser‐induced liquid bead ion desorption) in the analysis of nucleic acids and large oligonucleotides. For established methods like matrix‐assisted laser desorption/ionization (MALDI) and electrospray ionization (ESI), the mass analysis of oligonucleotides or of noncovalent oligonucleotide‐protein complexes, in particular of very large ones, still represents a considerable challenge either due to the lack of native solutions or nonspecific adduct formation or due to a reduced salt tolerance or a high charge state of the ions. With LILBID, oligonucleotides, solvated in micro‐droplets of aqueous buffer at certain pH and ion strength, are brought into the gas phase by laser ablation. We show that our method is able to detect single‐ and double‐stranded oligonucleotides with high softness, demonstrated by the buffer dependence of the melting of a duplex. The absolute sensitivity is in the attomole range concomitant with a total analyte consumption in the femtomole region. The upper mass limit of oligonucleotides still detected with good signal‐to‐noise ratio with LILBID is the 1.66 MDa plasmid pUC19. With DNA ladders from short duplexes with sticky ends, we show that LILBID correctly reflects the relative thermodynamic stabilities of the ladders. Moreover, as an example for a specific DNA–protein complex we show that a NF‐κB p50 homodimer binds sequence specifically to its match DNA. In summary we demonstrate that LILBID, although presently performed only with low mass resolution, due to these advantages, is an alternative mass spectrometric method for the analysis of oligonucleotides in general and of specific noncovalent nucleic acid–protein complexes in particular. Copyright © 2009 John Wiley & Sons, Ltd.
Compatibility of electron ionization and soft ionization methods in gas chromatography/orthogonal time‐of‐flight mass spectrometry
Authors: Hejazi Leila , Ebrahimi Diako , Hibbert D. Brynn , Guilhaus Michael
Published: June 2009

Orthogonal acceleration time‐of‐flight (oa‐TOF) mass spectrometry (MS) was coupled to gas chromatography (GC) to measure ion yields (ratio of ion counts to number of neutrals entering the ion source) and signal‐to‐noise (S/N) in the electron ionization (EI) mode (hard ionization) as well as in the soft ionization modes of chemical ionization (CI), electron capture negative ion chemical ionization (NICI) and field ionization (FI). Mass accuracies of the EI and FI modes were also investigated. Sixteen structurally diverse volatile organic compounds were chosen for this study. The oa‐TOF mass analyzer is highly suited for FI MS and provided an opportunity to compare the sensitivity of this ionization method to the more conventional ionization methods. Compared to the widely used quadrupole mass filter, the oa‐TOF platform offers significantly greater mass accuracy and therefore the possibility of determining the empirical formula of analytes. The findings of this study showed that, for the instrument used, EI generated the most ions with the exception of compounds able to form negative ions readily. Lower ion yields in the FI mode were generally observed but the chromatograms displayed greater S/N and in many cases gave spectra dominated by a molecular ion. Ion counts in CI are limited by the very small apertures required to maintain sufficiently high pressures in the ionization chamber. Mass accuracy for molecular and fragment ions was attainable at close to manufacturer's specifications, thus providing useful information on molecular ions and neutral losses. The data presented also suggests a potentially useful instrumental combination would result if EI and FI spectra could be collected simultaneously or in alternate scans during GC/MS. Copyright © 2009 John Wiley & Sons, Ltd.
Hydrophilic interaction chromatography/tandem mass spectrometry for the simultaneous determination of three polar non‐structurally related compounds, imipenem, cilastatin and an investigational β‐lactamase inhibitor, MK‐4698, in biological matrices
Authors: Xu Yang , Xie Wei , Miller‐Stein Cynthia M. , Woolf Eric J.
Published: June 2009

A method coupling hydrophilic interaction chromatography (HILIC) with tandem mass spectrometry (MS/MS) has been developed for the simultaneous determination of three polar non‐structurally related compounds – a carbapenem antibiotic, imipenem (IMP), a renal dehydropeptidase inhibitor, cilastatin (CIL), and an investigational β‐lactamase inhibitor, MK‐4698 (BLI), in rat plasma, monkey plasma and mouse blood. The analytes were extracted through protein precipitation, chromatographed on a Waters Atlantis HILIC column, and detected on a Sciex API4000 mass spectrometer using a Turbo‐Ion Spray ion source in positive ionization mode following multiple‐reaction monitoring (MRM). The assay dynamic range was 0.1–100 µg/mL for IMP, CIL and BLI, respectively, using a total of 20–25 µL biologic samples, and the total HPLC/MS/MS run time was 4 min/injection. The assay was found to be sensitive, selective and reproducible. The challenges, namely, sample stability, blood sample processing, matrix effect in monkey study samples, and dilution re‐assays for the limited mouse blood samples, are resolved and discussed. This technique allowed rapid analysis of polar compounds in biologic matrixes with satisfactory chromatographic retention and increased throughput. Copyright © 2009 John Wiley & Sons, Ltd.
Using multivariate statistical methods to model the electrospray ionization response of GXG tripeptides based on multiple physicochemical parameters
Authors: Raji M. A. , Fryčák P. , Temiyasathit C. , Kim S. B. , Mavromaras G. , Ahn J.‐M. , Schug K. A.
Published: June 2009

Response factors were determined for twelve GXG peptides (where G stands for glycine and X is any of alanine [A], arginine [R], asparagine [N], aspartic acid [D], glycine [G], histidine [H], leucine [L], lysine [K], phenylalanine [F], serine [S], tyrosine [Y], valine [V]) by electrospray ionization mass spectrometry (ESI‐MS). The response factors were measured using a novel flow injection method. This new method is based on the Gaussian distribution of analyte concentration resulting from band‐broadening dispersion experienced by the analyte upon passage through an extended volume of PEEK tubing. This method removes the need for preparing a discrete series of standard solutions to assess concentration‐dependent response. Relative response factors were calculated for each peptide with reference to GGG. The observed trends in the relative response factors were correlated with several analyte physicochemical parameters, chosen based on current understanding of ion release from charged droplets during the ESI process. These include analyte properties: nonpolar surface area; polar surface area; gas‐phase basicity; proton affinity; and Log D. Multivariate statistical analysis using multiple linear regression, decision tree, and support vector regression models were investigated to assess their potential for predicting ESI response based on the analyte properties. The support vector regression model was more versatile and produced the least predictive error following 12‐fold cross‐validation. The effect of variation in solution pH on the relative response factors is highlighted, as evidenced by the different predictive models obtained for peptide response at two pH values (pH = 6.0 and 9.0). The relationship between physicochemical parameters and associated ionization efficiencies for GXG tripeptides is discussed based on the equilibrium partitioning model. Copyright © 2009 John Wiley & Sons, Ltd.
Evolution of the BK polyomavirus: epidemiological, anthropological and clinical implications
Authors: Yogo Yoshiaki , Sugimoto Chie , Zhong Shan , Homma Yukio
Published: June 2009

BK polyomavirus (BKV) is essentially ubiquitous in all human populations worldwide. Asymptomatic infection with this virus occurs during early childhood, leading to life‐long persistence in the kidney. BKV has four subtypes that can be identified using serological and genotyping methods. The evolutionary aspects of BKV have remained poorly understood due to the limited availability of BKV genomes, since urinary excretion of BKV DNA is detected primarily in immunocompromised individuals. However, we have found that BKV DNA sequences can often be amplified from non‐immunocompromised elderly individuals, using a highly sensitive polymerase chain reaction (PCR) with highly concentrated urinary DNA as the source of viral DNA. Using this approach, we have PCR‐amplified and sequenced a large number of partial and complete BKV genomes from various human populations worldwide and conducted a series of evolutionary studies using these sequences. We have shown that subtypes I and IV evolved into four and six subgroups, respectively, with each having a close relationship with a particular human population. In addition, we have provided evidence supporting the hypothesis that BKV strains with the archetypal transcriptional control region (TCR) circulate in the human population. In this review, we describe these findings and discuss their epidemiological, anthropological and clinical implications. Copyright © 2009 John Wiley & Sons, Ltd.
Feature extraction through local learning
Authors: Sun Yijun , Wu Dapeng
Published: June 2009

RELIEF is considered one of the most successful algorithms for assessing the quality of features. It has been recently proved that RELIEF is an online learning algorithm that solves a convex optimization problem with a margin‐based objective function. Starting from this mathematical interpretation, we propose a novel feature extraction algorithm, referred to as local feature extraction (LFE), as a natural generalization of RELIEF. LFE collects discriminant information through local learning and can be solved as an eigenvalue decomposition problem with a closed‐form solution. A fast implementation of LFE is derived. Compared to principal component analysis, LFE also has a clear physical meaning and can be implemented easily with a comparable computational cost. Compared to other feature extraction algorithms, LFE has an explicit mechanism to remove irrelevant features. Experiments on synthetic and real‐world data are presented. The results demonstrate the effectiveness of the proposed algorithm. © 2009 Wiley Periodicals, Inc. Statistical Analysis and Data Mining 2: 34‐47, 2009
Different perspectives on internationalization in higher education
Authors: Kreber Carolin
Published: June 2009

Although internationalization efforts in higher education have become increasingly driven by economic considerations, this is not the case for all initiatives, particularly those at the level of curriculum, where academic, social/cultural, ethical, political, and even environmental rationales feature more strongly.
Reflections on trends and challenges in internationalizing an Ontario community college
Authors: Grabove Valerie L.
Published: June 2009

Market‐driven in its efforts to increase revenue, internationalization at Niagara College Canada is in evidence primarily at the institutional level and marginalized at the academic level. However, a byproduct has been the gradual evolution of internationalized academic programs and curricula as academic staff external to the International Department become more sensitive to and educated in the notion of internationalization.
Education for world‐mindedness: Beyond superficial notions of internationalization
Authors: Van Gyn Geraldine , Schuerholz‐Lehr Sabine , Caws Catherine , Preece Allison
Published: June 2009

An internationalized curriculum requires that we extend our actions far beyond concerns of course content to include pedagogies that promote cross‐cultural understanding and facilitate the development of the knowledge, skills, and values that will enable students, both domestic and international, to successfully engage with others in an increasingly interconnected and interdependent world.
From the inside out: Learning to understand and appreciate multiple voices through telling identities
Authors: Turniansky Bobbie , Tuval Smadar , Mansur Ruth , Barak Judith , Gidron Ariela
Published: June 2009

Internationalizing higher education is not simply a matter of adding international content. If one of the roles of higher education is to prepare students to survive and thrive in an uncertain, globalized world, we and our students have to develop a multicultural attitude that is both sensitive to, and appreciative of, cultural diversity.
The Sattvic curriculum: A three‐level, non‐Western, superstructure for undergraduate education
Authors: Haigh Martin
Published: June 2009

Instead of treating internationalization as the addition of multicultural elements to a Western curriculum, why not begin with a non‐Western curriculum framework?
Bridging the distance: Service learning in international perspective
Authors: Florman Jean C. , Just Craig , Naka Tomomi , Peterson Jim , Seaba Hazel H.
Published: June 2009

Partnering with Rotary International and residents of Xicotepec, Mexico, the University of Iowa Colleges of Engineering, Pharmacy, and Liberal Arts & Sciences have created a cross‐disciplinary, international service‐learning course whose impact through the years will respond to student‐learning and community‐identified needs.
Context‐oriented instructional design for course transformation
Authors: Perkins Ross A.
Published: June 2009

Colleagues from Virginia Tech and Mzuzu University personnel worked together to redesign an online master's degree program to fit Malawi's needs.
Internationalizing curriculum: A new kind of education?
Authors: Vainio‐Mattila Arja
Published: June 2009

Internationalization of the curriculum needs to be connected to a pedagogical discussion to be transformative.
Sustainability, internationalization, and higher education
Authors: Wright Tarah S. A.
Published: June 2009

Universities can contribute to a vision of global sustainability through research, teaching, and acting as models in their own physical operations. This chapter examines the role universities can and must play in achieving global sustainability and how this relates to the internationalization of the institution.
Effects of decabrominated diphenyl ether (PBDE 209) on voltage‐gated sodium channels in primary cultured rat hippocampal neurons
Authors: Xing Tai‐Ran , Yong Wu , Chen Liang , Tang Ming‐Liang , Wang Ming , Chen Ju‐Tao , Ruan Di‐Yun
Published: June 2009

Polybrominated diphenyl ethers (PBDEs) are widely used as flame‐retardant additives. But the application of PBDEs has been challenged due to their toxicity, especially neurotoxicity. In this study, we investigated the effects of decabrominated diphenyl ether (PBDE 209), the major PBDEs product, on voltage‐gated sodium channels (VGSCs) in primary cultured rat hippocampal neurons. Employing the whole‐cell patch‐clamp technique, we found that PBDE 209 could irreversibly decrease voltage‐gated sodium channel currents (INa) in a very low dose and in a concentration‐dependent manner. We had systematically explored the effects of PBDE 209 onINaand found that PBDE 209 could shift the activation and inactivation ofINatoward hyperpolarizing direction, slow down the recovery from inactivation ofINa, and decrease the fraction of activated sodium channels. These results suggested that PBDE 209 could affect VGSCs, which may lead to changes in electrical activities and contribute to neurotoxicological damages. We also showed that ascorbic acid, as an antioxidant, was able to mitigate the inhibitory effects of PBDE 209 on VGSCs, which suggested that PBDE 209 might inhibitINathrough peroxidation. Our findings provide new insights into the mechanism for the neurological symptoms caused by PBDE 209. © 2009 Wiley Periodicals, Inc. Environ Toxicol 25: 400–408, 2010.
The acute pulmonary toxicity in mice induced by multiwall carbon nanotubes, benzene, and their combination
Authors: Li Yi‐Song , Li Yu‐Feng , Li Qing‐Nuan , Li Jun‐Gang , Li Jing , Huang Qing , Li Wen‐Xin
Published: June 2009

Carbon nanotubes (CNTs) have been synthesized and produced on large scale for their wide application. They have high absorption ability to organic contaminants (such as benzene) and can form CNTs‐benzene combination with benzene. In this article, the acute pulmonary toxicity, induced by multiwall carbon nanotubes (MWCNTs), benzene, and their combination, was studied by administrating the three test materials into mice lungs via intratracheal instillation. The biochemical parameters in bronchoalveolar lavage fluid (BALF) and pathological lesions in lungs were used as endpoints to evaluate the pulmonary toxicity of the three test materials at 3‐day and 7‐day postexposure, respectively. After the mice were intratracheally instilled with MWCNTs, benzene and MWCNTs‐benzene combination at doses of 6.67 mg/kg, 2.67 mg/kg, and 9.34 mg/kg (containing 6.67 mg/kg MWCNTs and 2.67 mg/kg benzene), the total protein, alkaline phosphatase (ALP), acid phosphatase (ACP), and lactate dehydrogenase (LDH) in BALF and pathological lesions in lungs were examined. At 3‐day postexposure, MWCNTs induced obvious pulmonary toxicity and benzene only induced slight pulmonary toxicity, whereas their combination induced very severe pulmonary toxicity. At 7‐day postexposure, MWCNTs and benzene did not induce pulmonary toxicity individually, whereas their combination still induced severe pulmonary toxicity. These data indicated that, at the instilled doses in this experiment, the MWCNTs can alone induce acute pulmonary toxicity in mice and the benzene does not induce pulmonary toxicity, but the pulmonary toxicity of MWCNTs is enhanced after they form MWCNTs‐benzene combination with low dose of benzene. The enhanced pulmonary toxicity may be due to the change of MWCNTs aggregation ability after benzene is adsorbed on them. © 2009 Wiley Periodicals, Inc. Environ Toxicol 25: 409–417, 2010.
Accumulation of microcystins in water and fish tissues: An estimation of risks associated with microcystins in most of the Greek Lakes
Authors: Papadimitriou Theodoti , Kagalou Ifigenia , Bacopoulos Vasilios , Leonardos Ioannis D.
Published: June 2009

Toxin‐producing cyanobacteria in lakes and reservoirs form a threat to humans as well as various forms of aquatic life. This study is an investigation into the occurrence and distribution of Microcystins (MCYST) in 13 Greek Lakes. The distribution of MCYST in water and surface scum and toxin bioaccumulations in the omnivorous fish speciesCarassius gibeliowere surveyed in all lakes. Considerable amounts of MCYST were found in water and scum of all lakes, irrespective of the trophic state, the type of the lake, and the reported dominant cyanobacterial species. Toxin accumulation in six tissues (liver, brain, intestine, kidney, ovary, and muscle) ofC. gibeliowas also analyzed. Even though the target organ for MCYST is the liver, in our study, MCYST were found also in the rest ofC. gibeliotissues in the following order: liver > intestine > kidney > brain > ovaries > muscle. Risk assessments were carried out, taking into account the WHO guidelines and the tolerable daily intake (TDI) for MCYST. Our findings suggest that the amounts of MCYST found in water of Lakes Kastoria, Koronia, Pamvotis, Doirani, Mikri Prespa, Petron, and Zazari, pose adverse health risks. Also, it is likely to be unsafe to consumeC. gibelioin Lakes Koronia, Kastoria, Pamvotis, and Mikri Prespa due to the high concentrations of accumulated MCYST. © 2009 Wiley Periodicals, Inc. Environ Toxicol 25: 418–427, 2010.
In vivo indirect measurement of cytochrome P450‐associated activities in freshwater gastropod molluscs
Authors: Gagnaire Beatrice , Geffard Olivier , Noury Patrice , Garric Jeanne
Published: June 2009

The cytochrome P450 (CYP) system is widely distributed across phyla and plays a key role in the metabolism of xenobiotic compounds. However, most studies on CYP system were developed on vertebrates and among invertebrates, gastropod molluscs are rarely used. In this context, ethoxycoumarin‐O‐deethylase (ECOD), ethoxyresorufin‐O‐deethylase (EROD), and pentoxyresorufin‐O‐dealkylase (PROD) activities, which are indirect measurements of CYP system, were characterized in two freshwater gastropod molluscs, Potamopyrgus antipodarum, and Valvata piscinalis, to ascertain their potential interest as biomarkers of exposure to chemicals. Activities were measured using an in vivo non lethal method based on the measurement of formed product (resorufin or hydroxycoumarin). This in vivo assay allowed to measure the three activities in P. antipodarum and two of them (ECOD and PROD) in V. piscinalis. The detection of activities and the optimization of experimental design were carried out first and allowed to measure the selected activities for one individual. The modulation of the detected activities was secondly assessed using a polycyclic aromatic hydrocarbon (Benzo(a)pyrene). Based on this non destructive measurement, effect of BaP exposure could be detected on ECOD and EROD activity in P. antipodarum, as well on PROD activity of V. piscinalis after 96 h of exposure. Such an in vivo assay must be further developed to be valuably used to screen the exposure of gastropod species to CYP inducer chemicals and its consequences in terms of fitness of the organisms and of the population. © 2009 Wiley Periodicals, Inc. Environ Toxicol 25: 545–553, 2010.
Imaging in gynecological disease (5): clinical and ultrasound characteristics in fibroma and fibrothecoma of the ovary
Authors: Paladini D. , Testa A. , Van Holsbeke C. , Mancari R. , Timmerman D. , Valentin L.
Published: June 2009

Objectives

To describe the clinical and ultrasound features of fibroma and fibrothecoma of the ovary.

Methods

Sixty‐eight women with a histological diagnosis of fibroma or fibrothecoma of the ovary who had undergone a preoperative ultrasound examination between 1999 and 2007 were identified from the databases of four ultrasound centers. The tumors were characterized on the basis of ultrasound images, ultrasound reports and research protocols (when applicable) using the terms and definitions of the International Ovarian Tumor Analysis (IOTA) group. In 51 patients, ultrasound information had been collected prospectively; in the remaining 17 cases it was retrieved retrospectively from ultrasound reports and images. In 44 cases, electronic ultrasound images of good quality were available. These were reviewed by two observers, who described them using pattern recognition.

Results

Of the 68 patients identified, 53 had fibroma and 15 had fibrothecoma. The mean patient age was 54 (range, 17–80) years. Sixty‐three percent (41/65) were postmenopausal and 60% (39/65) had no symptoms. Most (75%; 51/68) fibromas/fibrothecomas were solid tumors and most (75%; 51/68) manifested minimal or moderate blood flow on color Doppler examination. Using pattern recognition, all solid fibromas/fibrothecomas were described as round, oval or slightly lobulated tumors. Most (66%; 29/44) were solid tumors, with regular or slightly irregular internal echogenicity with stripy shadows, and some contained cystic spaces. Others (23%, 10/44) were solid tumors with regular or slightly irregular internal echogenicity without stripy shadows and with or without cystic spaces. Two were solid tumors that were so dense it was difficult to assess their internal echogenicity, two were multilocular solid tumors with large cystic spaces and one was described as being mainly cystic. Half of the women with fibroma/fibrothecoma had fluid in the pouch of Douglas and 16% (11/68) had ascites; CA 125 titers ≥35 U/mL were found in 34% (17/50) of the cases in which CA 125 results were available.

Conclusions

Most fibromas and fibrothecomas are round, oval or lobulated solid tumors that cast stripy shadows and are associated with fluid in the pouch of Douglas, and most manifest minimal to moderate vascularization. A fibroma/fibrothecoma with atypical ultrasound appearance may be mistaken for a malignancy, in particular if associated with fluid in the pouch of Douglas or ascites, high color content and raised CA 125 levels. Copyright © 2009 ISUOG. Published by John Wiley & Sons, Ltd.
Anti‐herbivore effects of an ant species,Crematogaster difformis, inhabiting myrmecophytic epiphytes in the canopy of a tropical lowland rainforest in Borneo
Authors: Tanaka Hiroshi O. , Inui Yoko , Itioka Takao
Published: June 2009

Ants are believed to regulate herbivorous insects in the canopy of tropical rainforests, but few studies have empirically investigated the anti‐herbivore effects of the ants there. We examined the anti‐herbivore effects of the ant speciesCrematogaster difformis, which territorializes a large area of the crown of emergent canopy trees and inhabits the myrmecophytic epiphytes,Lecanopterissp. andPlatyceriumsp., which grow in the crown, by performing an ant‐exclusion experiment in the field. The average proportion of leaf area loss, the proportion of damaged leaves, and the proportion of leaves with ≥50% leaf area loss were all significantly higher on experimentally ant‐excluded branches than on ant‐attended branches at 3 months from the beginning of the ant‐exclusion treatment. These results suggest thatC. difformisregulates not only herbivorous insects that potentially feed on its host epiphytes but also those that could feed on leaves of emergent canopy trees that harbor the epiphytes.
Joint Procrustes Analysis for Simultaneous Nonsingular Transformation of Component Score and Loading Matrices
Authors: Adachi Kohei
Published: June 2009

In component analysis solutions, post-multiplying a component score matrix by a nonsingular matrix can be compensated by applying its inverse to the corresponding loading matrix. To eliminate this indeterminacy on nonsingular transformation, we propose Joint Procrustes Analysis (JPA) in which component score and loading matrices are simultaneously transformed so that the former matrix matches a target score matrix and the latter matches a target loading matrix. The loss function of JPA is a function of the nonsingular transformation matrix and its inverse, and is difficult to minimize straightforwardly. To deal with this difficulty, we reparameterize those matrices by their singular value decomposition, which reduces the minimization to alternately solving quartic equations and performing the existing multivariate procedures. This algorithm is assessed in a simulation study. We further extend JPA for cases where targets are linear functions of unknown parameters. We also discuss how the application of JPA can be extended in different fields.
The pathophysiology of restricted repetitive behavior
Authors: Lewis Mark , Kim Soo-Jeong
Published: June 2009

Restricted, repetitive behaviors (RRBs) are heterogeneous ranging from stereotypic body movements to rituals to restricted interests. RRBs are most strongly associated with autism but occur in a number of other clinical disorders as well as in typical development. There does not seem to be a category of RRB that is unique or specific to autism and RRB does not seem to be robustly correlated with specific cognitive, sensory or motor abnormalities in autism. Despite its clinical significance, little is known about the pathophysiology of RRB. Both clinical and animal models studies link repetitive behaviors to genetic mutations and a number of specific genetic syndromes have RRBs as part of the clinical phenotype. Genetic risk factors may interact with experiential factors resulting in the extremes in repetitive behavior phenotypic expression that characterize autism. Few studies of individuals with autism have correlated MRI findings and RRBs and no attempt has been made to associate RRB and post-mortem tissue findings. Available clinical and animal models data indicate functional and structural alterations in cortical-basal ganglia circuitry in the expression of RRB, however. Our own studies point to reduced activity of the indirect basal ganglia pathway being associated with high levels of repetitive behavior in an animal model. These findings, if generalizable, suggest specific therapeutic targets. These, and perhaps other, perturbations to cortical basal ganglia circuitry are mediated by specific molecular mechanisms (e.g., altered gene expression) that result in long-term, experience-dependent neuroadaptations that initiate and maintain repetitive behavior. A great deal more research is needed to uncover such mechanisms. Work in areas such as substance abuse, OCD, Tourette syndrome, Parkinson’s disease, and dementias promise to provide findings critical for identifying neurobiological mechanisms relevant to RRB in autism. Moreover, basic research in areas such as birdsong, habit formation, and procedural learning may provide additional, much needed clues. Understanding the pathophysioloy of repetitive behavior will be critical to identifying novel therapeutic targets and strategies for individuals with autism.
Modes in flow focusing and instability of coaxial liquid–gas jets
Authors: SI TING , LI FANG , YIN XIE-YUAN , YIN XIE-ZHEN
Published: June 2009

Six flow modes are distinguished in the flow-focusing experiments of a liquid jet forced by a high-speed air stream. The domains of the modes are identified on the parameter space of the liquid flow rateQland the gas pressure drop Δpg. The disturbance wavelength λ and breakup lengthLof the jet are also measured. A theoretical model considering axisymmetric disturbances is proposed, and a basic velocity profile of hyperbolic-tangent function is utilized. The linear temporal and spatio-temporal instability analyses are carried out using the Chebyshev collocation method. The effects of the flow parameters and the velocity profile on the flow instability are discussed. The temporal instability analysis demonstrates that the interfacial shear causes the instability of short waves and retards the instability of long waves. Moreover, the spatio-temporal instability analysis gives the transition boundary between the absolute and convective instability (AI/CI). The most unstable wavelength predicted by the temporal instability analysis and the AI/CI boundary predicted by the spatio-temporal instability analysis are in good agreement with the experimental results.
Effects of spatially varying roof cooling on thermal convection at high Rayleigh number in a fluid with a strongly temperature-dependent viscosity
Authors: JELLINEK A. M. , LENARDIC A.
Published: June 2009

We investigate the effects of an insulating lid of variable spatial extent on convection in the stagnant-lid regime under thermally steady-state conditions. Using a combination of laboratory experiments, numerical simulations and scaling analyses we characterize the qualitative structure and quantitative heat transfer properties of flows in terms of the fractional extent L of an insulating lid applied at the cold boundary, the thermal resistance of the lid, the magnitude of the temperature dependence of the fluid viscosity Λ and the effective Rayleigh number Rae for the composite system. A partial insulating lid has two main effects: (i) To increase the mean interior temperature and reduce the average viscosity of the system, which enhances fluid motions, and (ii) to impart a lateral asymmetry to the thermal structure of the cold boundary that leads, in turn, to lateral temperature gradients that drive an overturning flow. Consequently, whereas flow in the uninsulated stagnant-lid regime is in the form of ‘small-scale’ rising and sinking thermals, there is an additional ‘large-scale’ circulation in the presence of partial insulation. The structure, wavelength and heat transfer properties of this large-scale stirring depends on L, Λ and Rae. For given Rae – Λ conditions we find optimal values of L at which there occur well-defined maxima in the rate of overturn, the local heat flux carried into the uninsulated part of the cold boundary and in the global average heat flux Nu carried across the system. Whereas both the rate of overturning and local heat flux are associated with the largest lateral temperature gradients, the optimal basal heat flux depends also on a tradeoff with the fractional surface area of the lid. Remarkably, maximal values of the global heat flux can significantly exceed that of the uninsulated stagnant-lid case. The occurrence of such maxima is insensitive to the mechanical boundary conditions applied and is not strongly influenced by lid shape. However, the magnitude and location of optimal heat fluxes depends in a complicated way on the lid surface area and shape, as well as the structure of the hot and cold boundary layers and the wavelength of the large-scale flow.
On the origin of the inflectional instability of a laminar separation bubble
Authors: DIWAN SOURABH S. , RAMESH O. N.
Published: June 2009

This is an experimental and theoretical study of a laminar separation bubble and the associated linear stability mechanisms. Experiments were performed over a flat plate kept in a wind tunnel, with an imposed pressure gradient typical of an aerofoil that would involve a laminar separation bubble. The separation bubble was characterized by measurement of surface-pressure distribution and streamwise velocity using hot-wire anemometry. Single component hot-wire anemometry was also used for a detailed study of the transition dynamics. It was found that the so-called dead-air region in the front portion of the bubble corresponded to a region of small disturbance amplitudes, with the amplitude reaching a maximum value close to the reattachment point. An exponential growth rate of the disturbance was seen in the region upstream of the mean maximum height of the bubble, and this was indicative of a linear instability mechanism at work. An infinitesimal disturbance was impulsively introduced into the boundary layer upstream of separation location, and the wave packet was tracked (in an ensemble-averaged sense) while it was getting advected downstream. The disturbance was found to be convective in nature. Linear stability analyses (both the Orr–Sommerfeld and Rayleigh calculations) were performed for mean velocity profiles, starting from an attached adverse-pressure-gradient boundary layer all the way up to the front portion of the separation-bubble region (i.e. up to the end of the dead-air region in which linear evolution of the disturbance could be expected). The conclusion from the present work is that the primary instability mechanism in a separation bubble is inflectional in nature, and its origin can be traced back to upstream of the separation location. In other words, the inviscid inflectional instability of the separated shear layer should be logically seen as an extension of the instability of the upstream attached adverse-pressure-gradient boundary layer. This modifies the traditional view that pegs the origin of the instability in a separation bubble to the detached shear layer outside the bubble, with its associated Kelvin–Helmholtz mechanism. We contend that only when the separated shear layer has moved considerably away from the wall (and this happens near the maximum-height location of the mean bubble), a description by the Kelvin–Helmholtz instability paradigm, with its associated scaling principles, could become relevant. We also propose a new scaling for the most amplified frequency for a wall-bounded shear layer in terms of the inflection-point height and the vorticity thickness and show it to be universal.
PIV measurements of flow through a model porous medium with varying boundary conditions
Authors: ARTHUR JAMES K. , RUTH DOUGLAS W. , TACHIE MARK F.
Published: June 2009

This paper reports an experimental investigation of pressure-driven flow through models of porous media. Each model porous medium is a square array of circular acrylic rods oriented across the flow in a rectangular channel. The solid volume fraction φ of the arrays ranged from 0.01 to 0.49. Three boundary conditions were studied. In the first boundary condition, the model porous medium was installed on the lower wall of the channel only and was bounded by a free zone. In the second and third boundary conditions, porous media of equal and unequal φ were arranged on the lower and upper channel walls so that the two media touched (second boundary condition), and did not touch (third boundary condition). Using water as the working fluid, the Reynolds number was kept low so that inertia was not a factor. Particle image velocimetry was used to obtain detailed velocity measurements in the streamwise-transverse plane of the test section. The velocity data were used to study the effects of φ and the different boundary conditions on the flow through and over the porous medium, and at the interface. For the first boundary condition, it was observed that at φ = 0.22, flow inside the porous medium was essentially zero, and the slip velocity at the porous medium and free zone interface decayed with permeability. In the second and third boundary conditions, flow communication between the porous media was observed to be dependent on the combinations of φ used, and the trends of the slip velocities at the interface between the two porous media obtained for that boundary condition were indicative of complicated interfacial flow.
Drag and lift forces acting on a spherical gas bubble in homogeneous shear liquid flow
Authors: SUGIOKA KEN-ICHI , KOMORI SATORU
Published: June 2009

Drag and lift forces acting on a spherical gas bubble in a homogeneous linear shear flow were numerically investigated by means of a three-dimensional direct numerical simulation (DNS) based on a marker and cell (MAC) method. The effects of fluid shear rate and particle Reynolds number on drag and lift forces acting on a spherical gas bubble were compared with those on a spherical inviscid bubble. The results show that the drag force acting on a spherical air bubble in a linear shear flow increases with fluid shear rate of ambient flow. The behaviour of the lift force on a spherical air bubble is quite similar to that on a spherical inviscid bubble, but the effects of fluid shear rate on the lift force acting on an air bubble in the linear shear flow become bigger than that acting on an inviscid bubble in the particle Reynolds number region of 1≤Rep≤300. The lift coefficient on a spherical gas bubble approaches the lift coefficient on a spherical water droplet in the linear shear air-flow with increase in the internal gas viscosity.
Flow of a viscous incompressible fluid after a sudden point impulse near a wall
Authors: FELDERHOF B. U.
Published: June 2009

The flow of a viscous incompressible fluid generated by a sudden impulse near a wall with no-slip boundary condition is studied on the basis of the linearized Navier–Stokes equations. It turns out that the flow differs significantly from that for the perfect slip boundary condition, except far from the wall and at short times. At short time the flow is irrotational and can be described by a potential which varies with the square root of time. Correspondingly the pressure disturbance is quite large at short times. It shows an oscillation at later times if the impulse is directed parallel to the wall and decays monotonically for impulse perpendicular to the wall.
Available potential energy and buoyancy variance in horizontal convection
Authors: WINTERS KRAIG B. , YOUNG WILLIAM R.
Published: June 2009

We consider the mechanical energy budget for horizontal Boussinesq convection and show that there are two distinct energy pathways connecting the mechanical energy (i.e. kinetic, available potential and background potential energies) to the internal energy reservoir and the external energy source. To obtain bounds on the magnitudes of the energy transfer rates around each cycle, we first show that the volume-averaged dissipation rate of buoyancy variance χ ≡ κ 〈|∇b|2〉, where b is the buoyancy, is bounded from above by 4.57h−1κ2/3ν−1/3b7/3max. Here h is the depth of the container, κ the molecular diffusion, ν the kinematic viscosity and bmax the maximum buoyancy difference that exists on the surface. The bound on χ is used to estimate the generation rate of available potential energy Ea and the rate at which Ea is irreversibly converted to background potential energy via diapycnal fluxes, both of which are shown to vanish at least as fast as κ1/3 in the limit κ → 0 at fixed Prandtl number Pr = ν/κ. As a thought experiment, consider a hypothetical ocean insulated at all boundaries except at the upper surface, where the buoyancy is prescribed. The bounds on the energy transfer rates in the mechanical energy budget imply that buoyancy forcing alone is insufficient by at least three orders of magnitude to maintain observed oceanic dissipation rates and that additional energy sources such as winds, tides and perhaps bioturbation are necessary to sustain observed levels of turbulent dissipation in the world's oceans.
Steady nonlinear diffusion-driven flow
Authors: PAGE M. A. , JOHNSON E. R.
Published: June 2009

An imposed normal temperature gradient on a sloping surface in a viscous stratified fluid can generate a slow steady flow along a thin ‘buoyancy layer’ against that surface, and in a contained fluid the associated mass flux leads to a broader-scale ‘outer flow’. Previous analysis for small values of the Wunsch–Phillips parameter R is extended to the nonlinear case in a contained fluid, when the imposed temperature gradient is comparable with the background temperature gradient. As for the linear case, a compatibility condition relates the buoyancy-layer mass flux along each sloping boundary to the outer-flow temperature gradient. This condition allows the leading-order flow to be determined throughout the container for a variety of configurations.