bluuebunny/crossref_metadata_2025 huggingface dataset:
Invasive ductal carcinoma: correlation of apparent diffusion coefficient value with pathological prognostic factors
Authors: Razek Ahmed Abdel Khalek Abdel , Gaballa Gada , Denewer Adel , Nada Nadia
Published: March 2010

The aim of this study was to correlate the apparent diffusion coefficient (ADC) value of invasive ductal carcinoma with pathological prognostic factors. A prospective study was conducted on 59 untreated female patients (mean age 46 years) with invasive ductal carcinoma. All patients were examined at 1.5 Tesla using dedicated bilateral breast coil. They underwent diffusion weighted MR imaging of the breast using a single shot echo planar imaging with a b‐factor of 200 and 400 sec/mm2. Apparent diffusion coefficient (ADC) maps were reconstructed. The ADC value of the breast cancer was calculated and correlated with the pathologic prognostic factors (tumor size, grade and lymph nodes). The mean ADC values of invasive ductal carcinoma were significantly lower in patients with high grade, large breast cancer as well as those with axillary lymph nodes metastasis in a statistically significant way (p = 0.001 for the three factors). The mean ADC value of invasive ductal carcinoma was correlated with histologic grade (r = −0.675, p = 0.001), tumor size (r = 0.504, p = 0.001) and showed lower ADC values with positive lymph node metastasis. Apparent diffusion coefficient value is correlated with pathological parameters of invasive ductal carcinoma. The lower ADC values are associated with higher histological grade, larger tumor size and presence of axillary lymph nodes. So, the ADC value can be considered as a promising prognostic parameter that may identify highly aggressive breast cancer. Copyright © 2010 John Wiley & Sons, Ltd.
A MIP‐based local search method for the railway rescheduling problem
Authors: Acuna‐Agost Rodrigo , Michelon Philippe , Feillet Dominique , Gueye Serigne
Published: March 2010

For operational and unpredictable reasons, many small incidents occur day after day in rail transportation systems. Most of them have a local impact, but, in some cases, mainly in dense networks, minimal disruptions can spread out through the whole network and affect significantly the train schedules. In this article, we present the railway rescheduling problem as the problem of finding a new schedule of trains after one or several incidents by minimizing some measure of the effect. We investigate the solution of this problem through a mixed‐integer programming (MIP) formulation. Because of the impossibility for solving it exactly just using a standard MIP solver, we propose to limit the search space around the original nondisrupted schedule by hard and soft fixing of integer variables with local‐branching‐type cuts. Different variations of the method are compared to a right‐shift rescheduling policy in two different networks located in France and Chile. The experimental results are also used to study the impact of different objectives on the total delay. © 2010 Wiley Periodicals, Inc. NETWORKS, 2011
A client‐centred, occupation‐based occupational therapy programme for adults with psychiatric diagnoses
Authors: Schindler Victoria P
Published: March 2010

The purpose of this study was to assess the effectiveness of a client‐centred, occupation‐based occupational therapy programme for individuals with psychiatric diagnoses. The study took place in a college campus.

A pre‐test/post‐test design was used. There were 38 participants which included college students and community members who desired to attend college, work and/or address life skill goals. The Canadian Occupational Performance Measure (COPM) was used as a pre‐ and post‐test measure. Goals were based on problems identified in the COPM, reflected academic, vocational, life skill, and leisure goals, and were systematically addressed weekly through activities developed by the participant and a graduate occupational therapy student who acted as a mentor. The Participant Overall Satisfaction Scale was completed by each participant. A case study was used to describe the programme in more depth.

The results support that the client‐centred, occupation‐based occupational therapy programme increased client scores on satisfaction and performance of occupational performance problems identified on the COPM. Further research is recommended to explore how client‐centred occupational therapy programmes can be effective in improving academic, vocational and life skill goals. Copyright © 2010 John Wiley & Sons, Ltd.
Decentralization in Tanzania: An assessment of local government discretion and accountability
Authors: Venugopal Varsha , Yilmaz Serdar
Published: March 2010

A large part of the decentralization literature is fragmented along political, fiscal, or administrative lines. In this article we employ a diagnostic framework to draw these dimensions together in a coherent manner to focus on analyzing local government discretion and accountability in Tanzania. Tanzania seems to have a deconcentrated local government system with central appointees having large powers at the local level. Centrally‐funded mandates—such as constructing secondary schools—dominate local government plans and budgets. Central control over administrative functions has ensured that administrative decentralization is yet to occur. In the fiscal sphere, progress has been made in transparency and harmonization of transfers in the last 5 years but local governments still have some way to go in raising own revenues, being less reliant on transfers, and ensuring downward accountability. Copyright © 2010 John Wiley & Sons, Ltd.
A toxic mix? Comparative efficiency and the privatization of sanitation services in India
Authors: Murphy Jonathan
Published: March 2010

This article explores why the World Bank and its Indian government partners, in their efforts to reform the urban water and sanitation sector in India, have failed to recognize and address the intolerable working conditions of Dalit (outcaste) sanitation workers. The conceptual framework for the article is provided by the theory of thought‐styles, developed by Ludwig Fleck and refined by Mary Douglas, and its application to neoliberal public policy by the North American legal scholar Sharon Dolovich, who observed the domination of the principle of ‘comparative efficiency’ in US prison policy debates. This approach is applied to understanding how the worsening conditions of already highly vulnerable Dalit sewage workers have been displaced from the sanitation policy debate. Copyright © 2010 John Wiley & Sons, Ltd.
‘Pockets’ of effective agencies in weak governance states: Where are they likely and why does it matter?
Authors: Leonard David K.
Published: March 2010

It is well established that even in countries that have poor governance and weak public sectors, exceptional well‐functioning government and government‐supported agencies do exist. What has not been established is where and why these ‘pockets of effectiveness’ are able to emerge. Some attribute their existence to exceptional leadership and good management. Others, while not doubting the importance of these internal factors, believe that these ‘pockets’ are generated by their place in the country's political economy. The literature on this subject is dominated by case studies and the consequence is that a very large number of hypotheses have been generated about what the political processes at work might be. This article inventories the array of available hypotheses and condenses them into five sets of meta‐hypotheses. It also discusses how social scientists and practitioners ought to think about something whose occurrence is idiosyncratic. The future of development administration will be enhanced by more informed choice of strategic opportunities—avoiding both political determinism and a naïve faith that all is equally possible to those who will it. Copyright © 2010 John Wiley & Sons, Ltd.
Aortic isthmus Doppler velocimetry: role in assessment of preterm fetal growth restriction
Authors: Kennelly M. M. , Farah N. , Turner M. J. , Stuart B.
Published: March 2010

Intrauterine fetal growth restriction (IUGR) is an important pregnancy complication associated with significant adverse clinical outcome, stillbirth, perinatal morbidity and cerebral palsy. To date, no uniformly accepted management protocol of Doppler surveillance that reduces mortality and cognitive morbidity has emerged. Aortic isthmus (AoI) evaluation has been proposed as a potential monitoring tool for IUGR fetuses. In this review, the current knowledge of the relationship between AoI Doppler velocimetry and preterm fetal growth restriction is reviewed. Relevant technical aspects and reproducibility data are reviewed as we discuss AoI Doppler and its place within the existing repertoire of Doppler assessments in placental insufficiency. The AoI is a link between the right and left ventricles which perfuse the lower and upper body, respectively. The clinical use of AoI waveforms for monitoring fetal deterioration in IUGR has been limited, but preliminary work suggests that abnormal AoI impedance indices are an intermediate step between placental insufficiency‐hypoxemia and cardiac decompensation. Further prospective studies correlating AoI indices with arterial and venous Doppler indices and perinatal outcome are required before encorporating this index into clinical practice. Copyright © 2010 John Wiley & Sons, Ltd.
Nearly‐Kähler dimensional reduction of the heterotic string
Authors: Chatzistavrakidis A. , Zoupanos G.
Published: March 2010

The effective action in four dimensions resulting from the ten‐dimensional 𝒩 = 1 heterotic supergravity coupled to 𝒩 = 1 supersymmetric Yang‐Mills upon dimensional reduction over nearly‐Kähler manifolds is discussed. Nearly‐Kähler manifolds are an interesting class of manifolds admitting an SU(3)‐structure and in six dimensions all homogeneous nearly‐Kähler manifolds are included in the class of the corresponding non‐symmetric coset spaces plus a group manifold. Therefore it is natural to apply the Coset Space Dimensional Reduction scheme using these coset spaces as internal manifolds in order to determine the four‐dimensional theory.
Recent developments in automated NLO calculations: the HELAC‐NLO case
Authors: Bevilacqua G.
Published: March 2010

Achieving a precise description of multi‐parton final states is crucial for the interpretation of the LHC data. Recent years have seen a huge effort in developing methods for an efficient and fully automated computation of cross sections at the one‐loop level enlarging the wealth of predictions accessible at the next‐to‐leading order (NLO). In this proceedings contribution we briefly review the main features of the HELAC‐NLO method and show, as an illustratory example, some results of a complete NLO study of Higgs signal

versus irreducible QCD background in

production at the LHC.
Ulipristal acetate: emergency contraception for up to five days
Authors: Chaplin Steve , Cameron Sharon
Published: March 2010

Ulipristal acetate (EllaOne) is a new oral emergency contraceptive licensed for up to 120 hours following unprotected intercourse. In our New products review, Steve Chaplin presents the data relating to its efficacy and adverse effects and Dr Sharon Cameron discusses its role as an emergency contraceptive. Copyright © 2010 Wiley Interface Ltd
Affinity of synthetic peptide fragments of MyoD for Id1 protein and their biological effects in several cancer cells
Authors: Chen Chiu‐Heng , Kuo Sheng‐Chu , Huang Li‐Jiau , Hsu Mei‐Hua , Lung Feng‐Di T.
Published: March 2010

MyoD is a DNA‐binding protein capable of specific interactions that involve the helix–loop–helix (HLH) domain. The HLH motif of MyoD can form oligomers with the HLH motif of Id1 (the inhibitor of DNA‐binding proteins) that folds into a highly stable helical conformation stabilized by the self‐association. The Id family consists of four related proteins that contain a highly conserved dimerization motif known as the HLH domain. In signaling pathways, Id proteins act as dominant negative antagonists of the basic helix–loop–helix (bHLH) family of transcription factors which play important roles in cellular development, proliferation, and differentiation. The mechanism of Id proteins is to antagonize bHLH proteins by binding as dominant negative HLH proteins to form high‐affinity heterodimers with other bHLH proteins, thereby preventing them from binding to DNA and inhibiting transcription of differentiation‐associated genes. The goal of this study is to design and synthesize peptide fragments of MyoD with high affinity for Id1 to interrupt the interactions among Id1, MyoD, and other bHLH DNA‐binding proteins and to inhibit the proliferation of cancer cells. Affinity of each peptide for Id1 was determined by surface plasmon resonance (SPR) technology. The secondary structure of each peptide was studied by circular dichroism (CD) spectroscopy. Biological effects of each peptide in several cancer cells such as breast and colon cancer cells were analyzed. Results demonstrated that the peptide 3C (H‐Tyr‐Ile‐Glu‐Gly‐Leu‐Gln‐Ala‐Leu‐Leu‐Arg‐Asp‐Gln‐NH2) not only showed high affinity for Id1 but also exhibited antiproliferative effects in HT‐29 and MCF‐7 cancer cells; the IC50 value of 3C was determined as 25 µM in both cells. The percentage of sub‐G1 in the cell cycle of the cancer cells treated with 5 µM of 3C was increased, indicating the induced apoptosis of cancer cells by 3C. Taken together, the peptide 3C is a promising lead compound for the development of antiproliferative agents. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd.
Photoelectron spectroscopic study on electronic structure of butterfly‐templated ZnO
Authors: Kamada Masao , Sugiyama Harue , Takahashi Kazutoshi , Guo Qixin , Gu Jiajun , Zhang Wang , Fan Tongxiang , Zhang Di
Published: March 2010

Biological systems have complicated hierarchical architecture involving nano‐structures inside, and are expected as another candidate for new nano‐templates. The present work reports the photoelectron spectroscopic study on electronic structure of the butterfly‐templated ZnO that were successfully produced from butterfly wings. Ultraviolet Photoelectron Spectrum (UPS) of the butterfly‐templated ZnO shows clearly the valence band and a Zn‐3d peak, indicating that the butterfly‐templated ZnO has the same electronic structure as bulk ZnO. However, the detailes show that the energy positions of the Zn‐3d level and the valence‐band structure are different between them. The present results indicate that the bonding interaction between Zn‐4sp and O‐2p orbitals is stronger in the butterfly‐templated ZnO, probably due to the nano‐structures inside. Important parameters such as band bending and electron affinity are also obtained. The larger band bending and the lower electron affinity are found in the butterfly‐templated ZnO (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Energy transfer in ZnSe/(Zn,Mn)Se double quantum wells
Authors: Jankowski Stephanie , Heimbrodt Wolfram
Published: March 2010

The complex interplay of energy transfer and tunnelling processes in asymmetric ZnSe/(Zn,Mn)Se double quantum well structures has been investigated. The optical properties at low temperatures and in an external magnetic fields up to 7 T show remarkable differences to earlier studies on CdTe/(Cd,Mn)Te double quantum wells. The pure quantum‐mechanical tunnelling‐process is only a minor contribution to the field dependence of the emission even in case of small barriers and strong quantum‐well coupling (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Density functional study of AgnPd and AgnPdH clusters
Authors: Zhao Shuang , Ren Yunlai , Ren Yunli , Wang Jianji , Yin Weiping
Published: March 2010

Small AgnPd (n = 5) clusters and their hydrides AgnPdH (n = 5) have been studied by density functional theory calculations. For bare clusters, the structures in which the Pd atom has a maximum number of neighboring Ag atoms tend to be energetically favorable. Hydrogen prefers binding to AgPd bridge site of AgnPd clusters except for Ag5Pd. The binding energy has a strong odd–even oscillation. The electron transfers are from Ag atoms to Pd in bare clusters and are from metal clusters to H in cluster hydrides. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Anisotropic effect in collisions of ions with biomolecules
Authors: Bacchus‐Montabonel M. C. , Tergiman Y. S. , Talbi D.
Published: March 2010

An overview of the anisotropy effect in charge transfer processes induced by collision of ions on biomolecular targets is presented. The theoretical treatment includes ab‐initio molecular calculations of the potential energy curves and couplings followed by a semi‐classical collision dynamics. The method is presented for the case of direct processes by the example of the collision of C4+ ions on uracil and halouracil targets, and for the case of indirect processes corresponding to the action of ions on the medium, by the example of the C2+ + CO collision system. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Toward understanding the protein oxidation processes: •OH addition on tyrosine, phenylalanine, or methionine?
Authors: Trouillas Patrick , Bergès Jacqueline , Houée‐Lévin Chantal
Published: March 2010

Oxidation of peptides and proteins by •OH radicals produced in oxidative stress or in radiotherapy, accidental irradiations, etc., is well known to form oxidative metabolites that are responsible for numerous diseases including neurodegenerative pathologies. Tyrosine (Tyr), Phenylalanine (Phe), and Methionine (Met) residues are known to be the major targets of •OH radicals. This study aims at better understanding the •OH addition process on these three amino acids. On the basis of different amino acid prototypes, the Gibbs energy (ΔG) (B3P86/6‐31+G(d,p)) and rate constants (kTST) (MPWB1K/6‐31+G(d,p)) of •OH addition were calculated. The •OH addition capacity was studied (i) on the different positions of the aromatic rings of Tyr and Phe and (ii) on the S‐atom of Met. The addition was favored on the aromatic rings of Tyr and Phe with almost the same ΔGaddition values for both amino acids. No preferential position was found. The only parameter that may influence the OH‐adduct formation is the presence or absence of intra‐H bondings. In agreement with the experimental data available from the literature, the OH‐adduct on Met appeared to be less favored. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Can electron equilibration in excited Na8 clusters be interpreted as thermalization?
Authors: Nest M.
Published: March 2010

We report on recent progress toward bridging the gap between the fields of ab initio time‐dependent electronic structure theory on the one hand, and quantum statistics/thermodynamics on the other hand. It will be shown that Boltzmanns definition of temperature is more suitable, then the attempt to extract temperature information from a fit of the Fermi–Dirac distribution to populations of Hartree–Fock single particle states. However, the discrepancy between the two leads to the still open question of how to define an appropriate single particle picture. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Pd characterization by XPS in perovskite catalysts for NOx reduction: influence of thermal aging
Authors: Miquel P. , Yamin Y. , Lombaert K. , Dujardin C. , Trentesaux M. , Gengembre L. , Granger P.
Published: March 2010

This study reports surface characterizations of Pd/LaFeO3 catalysts after aging in diesel engine simulated conditions. Thermal aging and support‐induced effects on the nature of Pd species were investigated. LaFeO3 was prepared via a sol–gel method to promote relatively high specific surface area (19 m2 g−1). Subsequent impregnation from solutions using Pd(NO3)2, Pd(acac)2 or Pd(NH3)4(NO3)2 precursor salts was examined by means of XPS and infrared spectroscopy on pre‐activated catalysts under reductive atmosphere and aged ones under reactive conditions overnight at 500 °C. Both techniques reveal that the degree of Pd dispersion and the reducibility of oxidic palladium species are correlated to the oxidation state of oxidic palladium species and depend on the nature of the precursor salt. Hence, impregnated samples using Pd(NH3)4(NO3)2 and Pd(acac)2 precursor salts, after calcination, lead to highly dispersed Pd4+ species strongly interacting with the support. On the other hand, it was found that both the catalysts suffer from stronger deactivation phenomena than those affecting the catalysts prepared via Pd(NO3)2. Copyright © 2010 John Wiley & Sons, Ltd.
Mammary Epithelial Reconstitution with Gene-Modified Stem Cells Assigns Roles to Stat5 in Luminal Alveolar Cell Fate Decisions, Differentiation, Involution, and Mammary Tumor Formation
Authors: Vafaizadeh Vida , Klemmt Petra , Brendel Christian , Weber Kristoffer , Doebele Carmen , Britt Kara , Grez Manuel , Fehse Boris , Desriviéres Sylvane , Groner Bernd
Published: March 2010

The mammary gland represents a unique model system to study gene functions in adult stem cells. Mammary stem cells (MaSCs) can regenerate a functional epithelium on transplantation into cleared fat pads. We studied the consequences of distinct genetic modifications of MaSCs on their repopulation and differentiation ability. The reconstitution of ductal trees was used as a stem cell selection procedure and the nearly quantitative lentiviral infection efficiency of the primary mammary epithelial cells (MECs) rendered the enrichment of MaSCs before their transplantation unnecessary. The repopulation frequency of transduced MaSCs was nearly 100% in immunodeficient recipients and the resulting transgenic ducts homogeneously expressed the virally encoded fluorescent marker proteins. Transplantation of a mixture of MECs, expressing different fluorescent proteins, resulted in a distinct pattern of ductal outgrowths originating from a small number of individually transduced MaSCs. We used genetically modified MECs to define multiple functions of Stat5 during mammary gland development and differentiation. Stat5-downregulation in MaSCs did not affect primary ductal outgrowth, but impaired side branching and the emergence of mature alveolar cells from luminal progenitors during pregnancy. Conversely, the expression of a constitutively active variant of Stat5 (cS5-F) caused epithelial hyperproliferation, thickening of the ducts and precocious, functional alveoli formation in virgin mice. Expression of cS5-F also prevented involution and caused the formation of estrogen and progesterone receptor positive (ER+PR+) adenocarcinomas. The tumors expressed activated Stat5 and Stat3 and contained a small fraction of CD44+ cells, possibly indicative of cancer stem cells.
Students' comprehension of science textbooks using a question‐based reading strategy
Authors: Smith Betty Lou , Holliday William G. , Austin Homer W.
Published: March 2010

Despite the heavy reliance on textbooks in college courses, research indicates that college students enrolled in first‐year science courses are not proficient at comprehending informational text. The present study investigated a reading comprehension questioning strategy with origins in clinical research based in elaboration interrogation theory, which outlines how to encourage readers to recall relevant background knowledge while reading text materials. The theory suggests that the strategy increases the likelihood that readers will integrate what they read with what they know to make new knowledge. The setting for the study more closely resembled classroom conditions compared to similar studies in the past. Unlike previous studies on reading comprehension, students read a challenging passage from the textbook used in a science course in which they were enrolled. In addition, the text was longer than that used in clinical research. The college students (n = 294) in this study were randomly assigned to either a questioning strategy treatment or a rereading placebo‐control. While reading, treatment students were presented with statements taken from regular intervals in their textbook (about every 150 words) and asked a simple why question about each of these statements. Significant differences were found favoring elaborative interrogation theory and its question strategy treatment over the placebo‐control in terms of science comprehension even after significant estimated predictors of prior knowledge and verbal ability were statistically controlled or accounted for by removing the statistical contributions of these predictors to the main effects. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 363–379, 2010
Sozialräumliche Segregation in London
Authors: Zehner Klaus
Published: March 2010

The economic restructuring of global cities is reflected by the polarisation of their labour markets. The huge differences of salaries result in social polarisation and in a noticeable segregation of quarters particularly within inner city residential areas. The goal of this paper is to present a formula that measures and quantifies the degree of social segregation within quarters. The analysis is based on the 2001 census data.
A more patient-friendly use of circular fixators in deformity correction
Authors: Sakkers Ralph J. , van der Wal A. J. , Dijkstra P. T. , Jaspers J. E. N.
Published: March 2010

Purpose

The evaluation of a construction that allows the exchange of circular and unilateral external fixators on the same fixation pins to the bone in outpatient circumstances during bone lengthening and alignment procedures.

Methods

Nine children were treated with this concept. After bone lengthening and alignment, the circular fixators were exchanged for unilateral fixators in the outpatient clinic to hold the position of the bony parts during the consolidation phase.

Results

The decrease of time needed to use the circular fixator during the treatment was considered to be an improvement in comfort.

Conclusions

The concept of using both a circular and a unilateral external fixator in a construction that allows the exchange of the external fixators in outpatient circumstances combines the advantages of both systems, and creates more options in the different stages of bone deformity correction. Patient comfort is increased by the decrease of time needed to use the circular fixator.
Mutant p62/SQSTM1 UBA domains linked to Paget's disease of bone differ in their abilities to function as stabilization signals
Authors: Heinen Christian , Garner Thomas P. , Long Jed , Böttcher Claudia , Ralston Stuart H. , Cavey James R. , Searle Mark S. , Layfield Robert , Dantuma Nico P.
Published: March 2010

We show that the ubiquitin‐associated domain (UBA) of human p62/sequestosome‐1 (SQSTM1) can delay degradation of proteasome substrates in yeast. Taking advantage of naturally occurring mutant UBA domains that are linked to Paget's disease of bone (PDB), we found that three of the four mutant UBA domains tested in this study were able to inhibit proteasomal degradation, albeit not to the same extent as the wild‐type domain. Interestingly, the stability measured as the fraction of folded protein, and not the ubiquitin binding properties, of the PDB‐associated UBA domains correlated with their protective effects. These data suggest that the protective effect of UBA domains depends on their structural integrity rather than ubiquitin binding capabilities.
Altered circadian rhythm of the clock genes in fibrotic livers induced by carbon tetrachloride
Authors: Chen Peng , Kakan Xiamusiya , Zhang Jianfa
Published: March 2010

Disruption in circadian rhythms either by mutation in mice or by shiftwork in people, is associated with an increased risk for the development of multiple organ diseases. In turn, organ disease may influence the function of clock genes and peripheral circadian systems. Here we showed that hepatic fibrosis induced by carbon tetrachloride in mice leads to alterations in the circadian rhythms of hepatic clock genes. Especially, we found an impaired daily Cry2 rhythm in the fibrotic livers, with markedly decreased levels during the day time while compared with control livers. Associatively, the expressions of two important clock‐regulated genes peroxisome proliferator‐activated receptor alpha and cytochrome P450 oxidoreductase lost circadian rhythm with significantly decreased levels during the light–dark (12/12 h) cycle in fibrotic livers.
A lithofacies description of Jurassic sediments in the south of the Predyenisei petroleum subprovince, West Siberia
Authors: Vakulenko L.G. , Aksenova T.P. , Yeltsov I.S. , Zamirailova A.G. , Yan P.A.
Published: March 2010

We have studied Jurassic sections in the Predyenisei subprovince of the West Siberian petroleum basin, which were penetrated in the Vostok-1, Vostok-3, and Vostok-4 stratigraphic wells. The Urman, Togur, Ilan, Peshkovo, Tyumen’, Naunak, and Mar’yanovka Formations are described from a detailed comprehensive core analysis and log data. The depositional environment for these sediments was predominantly continental. There is evidence for short transgressions in the Ilan (Lower Toarcian) and Peshkovo (Upper Toarcian) Formations, as well as the Upper Urman (Upper Pliensbachian) and the Upper Tyumen’ (Bajocian) Subformations. In the Upper Naunak Subformation (Oxfordian), there was a change of facies from continental to littoral continental and littoral marine. The Mar’yanovka Formation developed in normal marine shallow- or moderately deep-water environments. Although good reservoirs are common throughout the Jurassic section in the southeast of West Siberia, only small, lithologically screened deposits are predicted here.
New data on Quaternary morpholithogenesis in the Chuya basin (Gorny Altai)
Authors: Zol’nikov I.D. , Deev E.V. , Lyamina V.A.
Published: March 2010

New data have been obtained on the paleogeographic and stratigraphic assignment of Neopleistocene morpholithogenesis in the Chuya basin. They were derived from analysis of topographical maps, digital elevation models, and medium- and high-resolution satellite images as well as a textural and facies description of Quaternary sections. Near the basin side, a paragenetic association of sediments is widespread. These sediments, laid down by fluid debris flows and mudflows, formed a ridged terrain during the emptying of a Late Quaternary paleolake. A diluvial–erosional origin of a series of small parallel scarps has been suggested. They are usually interpreted as wave-cut benches, which mark temporary levels of a glacier-dammed lake. We have examined geological evidence for a high glacial dam with an age of maximum glaciation inside the Chuya basin. Because of the dam, glacier floods during the Middle Neopleistocene were larger than those during the Late Neopleistocene.
Experimental study of the system H3BO3–NaF–SiO2-H2O at 350–800 °C and 1–2 kbar by the method of synthetic fluid inclusions
Authors: Peretyazhko I.S. , Smirnov S.Z. , Kotel’nikov A.R. , Kotel’nikova Z.A.
Published: March 2010

The phase state of fluid in the system H3BO3–NaF–SiO2–H2O was studied at 350–800 °C and 1–2 kbar by the method of synthetic fluid inclusions. The increase in the solubility of quartz and the high reciprocal solubility of H3BO3 and NaF in water fluid at high temperatures are due to the formation of complexes containing B, F, Si, and Na. At 800 °C and 2 kbar, both liquid and gas immiscible phases (viscous silicate-water-salt liquid and three water fluids with different contents of B and F) are dispersed within each other. The Raman spectra of aqueous solutions and viscous liquid show not only a peak of [B(OH)3]0 but also peaks of complexes [B(OH)4]–, polyborates [B4O5(OH)4]2–, [B3O3(OH)4]–, and [B5O6(OH)4]–, and/or fluoroborates [B3F6O3]3–, [BF2(OH)2]–, [BF3(OH)]–, and [BF4]–. The high viscosity of nonfreezing fluid is due to the polymerization of complexes of polyborates and fluorine-substituted polyborates containing Si and Na. Solutions in fluid inclusions belong to P–Q type complicated by a metastable or stable immiscibility region. Metastable fluid equilibria transform into stable ones owing to the formation of new complexes at 800 ºC and 2 kbar as a result of the interaction of quartz with B-F-containing fluid. At high concentrations of F and B in natural fluids, complexes containing B, F, Si, and alkaline metals and silicate-water-salt dispersed phases might be produced and concentrate many elements, including ore-forming ones. Their transformation into vitreous masses or viscous liquids (gels, jellies) during cooling and the subsequent crystallization of these products at low temperatures (300–400 °C) should lead to the release of fluid enriched in the above elements.
The Earth’s magnetic field history for the past 400 Myr
Authors: Kurazhkovskii A.Yu. , Kurazhkovskaya N.A. , Klain B.I. , Bragin V.Yu.
Published: March 2010

Published and new data on the Earth’s past magnetic field have been interpreted in terms of its links with the frequency of magnetic polarity reversals and with tectonic events such as plume-related eruptions and rifting. The paleointensity and reversal frequency variations show an antiphase correlation between 0 and 160 Ma, and the same tendency likely holds for the past 400 Myr. The geomagnetic field intensity averaged over geological ages (stages) appears to evolve in a linearly increasing trend while its variations increase proportionally in amplitude and change in structure. Both paleointensity and reversal frequency patterns correlate with rifting and eruption events. In periods of high rifting activity, the geomagnetic field increases (15 to 30%) and the reversals become about 40% less frequent. Large eruption events between 0 and 150 Ma have been preceded by notable changes in magnetic intensity which decreases and then increases, the lead being most often within a few million years.
Flow-induced vibrations of a deformable ring
Authors: SHOELE KOUROSH , ZHU QIANG
Published: March 2010

To understand flow-induced vibrations of deformable objects, we numerically investigate dynamics of a pressurized elastic ring pinned at one point within a uniform flow by using an immersed-boundary algorithm. The boundary of the ring consists of a fibre with no bending stiffness, which can be modelled as a linear spring with spring constant k and zero unstretched length. The vibration of the ring is decomposed into two parts: a pitching motion that includes a rigid-body rotation and a flexible bending motion in the transverse direction, and a tapping motion in the longitudinal direction. The pitching motion is dominated by the frequency of vortex shedding, whereas the primary frequency of the tapping motion is twice the frequency of vortex shedding. At the Reynolds number of 100, resonance is observed when k ~ 0.2 (k is normalized by the diameter of the undeformed ring, the speed of the upcoming flow and the fluid density). Across the resonance region, abrupt jumps in terms of the motion amplitudes as well as the hydrodynamic loads are recorded. Within the resonance region, the lift force demonstrates a beating phenomenon reminiscent of findings through reduced models and low-degree-of-freedom systems.
Global three-dimensional optimal disturbances in the Blasius boundary-layer flow using time-steppers
Authors: MONOKROUSOS ANTONIOS , ÅKERVIK ESPEN , BRANDT LUCA , HENNINGSON DAN S.
Published: March 2010

The global linear stability of the flat-plate boundary-layer flow to three-dimensional disturbances is studied by means of an optimization technique. We consider both the optimal initial condition leading to the largest growth at finite times and the optimal time-periodic forcing leading to the largest asymptotic response. Both optimization problems are solved using a Lagrange multiplier technique, where the objective function is the kinetic energy of the flow perturbations and the constraints involve the linearized Navier–Stokes equations. The approach proposed here is particularly suited to examine convectively unstable flows, where single global eigenmodes of the system do not capture the downstream growth of the disturbances. In addition, the use of matrix-free methods enables us to extend the present framework to any geometrical configuration. The optimal initial condition for spanwise wavelengths of the order of the boundary-layer thickness are finite-length streamwise vortices exploiting the lift-up mechanism to create streaks. For long spanwise wavelengths, it is the Orr mechanism combined with the amplification of oblique wave packets that is responsible for the disturbance growth. This mechanism is dominant for the long computational domain and thus for the relatively high Reynolds number considered here. Three-dimensional localized optimal initial conditions are also computed and the corresponding wave packets examined. For short optimization times, the optimal disturbances consist of streaky structures propagating and elongating in the downstream direction without significant spreading in the lateral direction. For long optimization times, we find the optimal disturbances with the largest energy amplification. These are wave packets of Tollmien–Schlichting waves with low streamwise propagation speed and faster spreading in the spanwise direction. The pseudo-spectrum of the system for real frequencies is also computed with matrix-free methods. The spatial structure of the optimal forcing is similar to that of the optimal initial condition, and the largest response to forcing is also associated with the Orr/oblique wave mechanism, however less so than in the case of the optimal initial condition. The lift-up mechanism is most efficient at zero frequency and degrades slowly for increasing frequencies. The response to localized upstream forcing is also discussed.
A structure-based model for turbulent-boundary-layer wall pressures
Authors: AHN B.-K. , GRAHAM W. R. , RIZZI S. A.
Published: March 2010

Practical prediction of structural vibrations due to a turbulent boundary layer currently depends on empirical representations of the unsteady wall pressures. Improvements in these representations would be greatly facilitated if a simple, physically based model were available to test ad hoc assumptions and provide rigorous interpolation of experimental data. A possible candidate is the attached-eddy model, developed from Townsend's initial ideas by Perry and co-workers in the context of turbulence velocity spectra. This approach employs the superposition of contributions from individual ‘eddies’, of varying size, to yield its predictions. It is shown here that the same methodology can be applied for wall pressures, once the field due to an eddy has been obtained via solution of the governing Poisson equation. Comparisons with large-eddy simulation and experimental data, spanning a two-decade Reynolds number range, show remarkably good agreement, given the simplicity of the model. It is concluded that this approach has the potential to provide useful physical insight and, subject to its extension to a time-resolved form, improvements to existing empirical formulations.
Regimes of thermocapillary migration of droplets under partial wetting conditions
Authors: GOMBA J. M. , HOMSY G. M.
Published: March 2010

We study the thermocapillary migration of two-dimensional droplets of partially wetting liquids on a non-uniform heated substrate. An equation for the thickness profile of the droplet is derived by employing lubrication approximations. The model includes the effect of a non-zero contact angle introduced through a disjoining–conjoining pressure term. Instead of assuming a fixed shape for the droplet, as in previous works, here we allow the droplet to change its profile with time. We identify and describe three different regimes of behaviour. For small contact angles, the droplet spreads into a long film profile with a capillary ridge near the leading edge, a behaviour that resembles the experiments on Marangoni films reported by Ludviksson & Lightfoot (Am. Inst. Chem. Eng. J., vol. 17, 1971, pp. 1166). For large contact angles, the droplet moves as a single entity, weakly distorted from its static shape. This regime is the usual one reported in experiments on thermocapillary migration of droplets. We also show some intriguing morphologies that appear in the transition between these two regimes. The occurrence of these three regimes and their dependence on various parameters is analysed.
The nonlinear dynamics of pendent drops on a thin film coating the underside of a ceiling
Authors: LISTER JOHN R. , RALLISON JOHN M. , REES SIMON J.
Published: March 2010

This paper considers the dynamics of a thin film of viscous liquid of density ρ coating the underside of a horizontal rigid boundary under the action of surface tension σ and gravity g, and in the lubrication limit. Gravitational instability for inverse wavenumbers larger than the capillary length ℓ = (σ/ρg)1/2) leads to the formation of quasi-static pendent drops of radius ≈3.83ℓ. If the boundary conditions are such as to pin the positions of the drops then the drops slowly drain fluid from the regions between them through thin annular trenches around each drop. A similarity solution is derived and verified numerically in which the film thickness in the intervening regions scales like t−1/4 and that in the trenches like t−1/2. A single drop placed far from boundaries on an otherwise uniform film, and given an initial perturbation, undergoes self-induced quasi-steady translation during which it grows slowly in amplitude by leaving a wake where the film thickness is reduced by an average of 90. It is driven by release of gravitational potential energy as fluid is collected from the film into the lower lying drop. Analysis of Landau–Levich regions around the perimeter of the translating drop predicts its speed and the profile of the wake. Two translating drops may coalesce if they collide, in contrast with the non-coalescence of colliding collars in the analogous one-dimensional problem (Lister et al., J. Fluid Mech. vol. 552, 2006b, p. 311). Colliding drops may also bounce off each other, the outcome depending on the angle of incidence through complex interactions between their surrounding capillary wave fields.
Stephen H. Davis – 70, and counting
Authors: NEITZEL G. PAUL
Published: March 2010

Celebrating the occasion of his 70th birthday, observations are offered on the life and technical contributions of Stephen H. Davis, Editor of the Journal of Fluid Mechanics.
VARIABILITY FOR CARRIER-BORNE EPIDEMICS AND REED–FROST MODELS INCORPORATING UNCERTAINTIES AND DEPENDENCIES FROM SUSCEPTIBLES AND INFECTIVES
Authors: Ortega Eva María , Escudero Laureano F.
Published: March 2010

This article provides analytical results on which are the implications of the statistical dependencies among certain random parameters on the variability of the number of susceptibles of the carrier-borne epidemic model with heterogeneous populations and of the number of infectives under the Reed–Frost model with random infection rates. We consider dependencies among the random infection rates, among the random infectious times, and among random initial susceptibles of several carrier-borne epidemic models. We obtain conditions for the variability ordering between the number of susceptibles for carrier-borne epidemics under two different random environments, at any time-scale value. These results are extended to multivariate comparisons of the random vectors of populations in the strata. We also obtain conditions for the increasing concave order between the number of infectives in the Reed–Frost model under two different random environments, for any generation. Variability bounds are obtained for different epidemic models from modeling dependencies for a range of special cases that are useful for risk assessment of disease propagation.
Characterization of finite type string link invariants of degree <5
Authors: MEILHAN JEAN-BAPTISTE , YASUHARA AKIRA
Published: March 2010

We give a complete set of finite type string link invariants of degree <5. In addition to Milnor invariants, these include several string link invariants constructed by evaluating knot invariants on certain closures of (cabled) string links. We show that finite type invariants classify string links up toCk-moves fork≤ 5, which proves, at low degree, a conjecture due to Goussarov and Habiro. We also give a similar classification of string links up toCk-moves and concordance fork≤ 6.
Partial Castelnuovo–Mumford regularities of sums and intersections of powers of monomial ideals
Authors: HOA LÊ TUÂN , TRUNG TRÂN NAM
Published: March 2010

Let I, I11,. . ., I1q1,. . ., Ip1,. . ., Ipqp be monomial ideals of a polynomial ring R = K[X1,. . ., Xr] and Ln = I+∩jIn1j + ⋅ ⋅ ⋅ + ∩jIpjn. It is shown that the ai-invariant ai(R/Ln) is asymptotically a quasi-linear function of n for all n ≫ 0, and the limit limn→∞ad(R/Ln)/n exists, where d = dim(R/L1). A similar result holds if I11,. . ., I1q1,. . ., Ip1,. . ., Ipqp are replaced by their integral closures. Moreover all limits $\lim_{n\to\infty} a_i(R/(\cap_j \overline{I_{1j}^n} + \cdots + \cap_j \overline{I_{pj}^n}))/n $ also exist.

As a consequence, it is shown that there are integers p > 0 and 0 ≤ e ≤ d = dim R/I such that reg(In) = pn + e for all n ≫ 0 and pn ≤ reg(In) ≤ pn + d for all n > 0 and that the asymptotic behavior of the Castelnuovo–Mumford regularity of ordinary symbolic powers of a square-free monomial ideal is very close to a linear function.
The Listing of Chinese State-Owned Banks and their Path to Banking and Ownership Reform
Authors: McGuinness Paul B. , Keasey Kevin
Published: March 2010

China's leading state-owned banks have undergone radical transformation in recent years, with six of the country's top seven players listed in both Hong Kong and Shanghai. We first consider how the banks were reorganized for initial public offering, in terms of the removal of non-performing loans and the massive recapitalization of their balance sheets. Second, and more importantly, we consider whether they have been able to retain market share, further commercialize and enhance overall financial positions post-listing. Through in-depth case analysis of the six state-owned banks, we show that post-initial public offering they have significantly improved profitability, loan book size, loan book quality and capital reserve protection. However, we caution that the debilitating effects of the global credit crunch may slow or even arrest further progress across these dimensions in the near term. We conclude that China's leading banks have benefited materially from their transition, and have accordingly developed a range of competitive and co-operative strategies not only to sustain domestic market advantage but also to penetrate overseas markets.
An observational study of consumer use of fast-food restaurant drive-through lanes: implications for menu labelling policy
Authors: Roberto Christina A , Hoffnagle Elena , Bragg Marie A , Brownell Kelly D
Published: March 2010

Objective

Some versions of restaurant menu labelling legislation do not require energy information to be posted on menus for drive-through lanes. The present study was designed to quantify the number of customers who purchase fast food through drive-in windows as a means of informing legislative labelling efforts.

Design

This was an observational study.

Setting

The study took place at two McDonald’s and Burger King restaurants, and single Dairy Queen, Kentucky Fried Chicken, Taco Bell and Wendy’s restaurants.

Subjects

The number of customers entering the chain restaurants and purchasing food via the drive-through lane were recorded. A total of 3549 patrons were observed.

Results

The percentage of customers who made their purchases at drive-throughs was fifty-seven. The overall average (57 %) is likely a conservative estimate because some fast-food restaurants have late-night hours when only the drive-throughs are open.

Conclusions

Since nearly six in ten customers purchase food via the drive-through lanes, menu labelling legislation should mandate the inclusion of menu labels on drive-through menu boards to maximise the impact of this public health intervention.