bluuebunny/crossref_metadata_2025 huggingface dataset:
Structural domain–domain interactions: Assessment and comparison with protein–protein interaction data to improve the interactome
Authors: Prieto C. , De Las Rivas J.
Published: August 2009

Assessment and improvement of the reliability of protein–protein interaction (ppi) data is critical for the progress of the currently active research on interactomes. Some interesting questions in this respect are: How three‐dimensional (3D) protein structural data is present in known ppi data?, and How this kind of information can be used to validate and improve the interactomes? To address this problem, analysis and unification of six structural domain–domain interaction (sddi) datasets is presented; followed by a comparative study of these sddi data in three ppi reference sets produced at different levels of confidence. The results show that protein structural and interactomic data are partially complementary and that a larger proportion of structural information is observed in more confident interactomes. We also present, focused on the human interactome, an analysis of the domains that are more frequently present in: (i) an interactome based on validation by at least two experimental methods versus (ii) another interactome based on validation by 3D structural interaction data. These results allow to distinguish between domain pairs associated to protein interactions supported by 3D structures and domain pairs that at present are not supported by structural information. The domain pairs exclusive of interactions without associated 3D data reveal interacting conserved modules that are probably flexible, disordered, and difficult to crystallize; and which are often found in proteins involved in signaling pathways and DNA processing. Proteins 2010. © 2009 Wiley‐Liss, Inc.
A laboratory evaluation to determine the compatibility of microbiological control agents with the pollinator Bombus terrestris
Authors: Mommaerts Veerle , Sterk Guido , Hoffmann Lucien , Smagghe Guy
Published: August 2009

BACKGROUND: This study was undertaken to identify any potential adverse side effects of the use of seven microbiological control agents (MCAs) on the bumblebee, Bombus terrestris L., in the context of combined use in integrated pest management (IPM). AQ10® (Ampelomyces quisqualis), Binab‐T‐vector® (Hypocrea parapilulifera + T. atroviride; 1/1), Prestop‐Mix® (Gliocladium catenulatum J1446), Serenade® (Bacillus subtilis QST713), Trianum‐P® (Trichoderma harzianum T22), Botanigard® (Beauveria bassiana GHA) and Granupom® (Cydia pomonella granulovirus), comprising five biofungicides and two bioinsecticides, were investigated. Bumblebee workers were exposed under laboratory conditions to each MCA at its maximum field recommended concentration (MFRC) via three different routes of exposure: dermal contact and orally via either treated sugar water or pollen.

RESULTS: The tested MCAs were found to be safe for workers of B. terrestris, with the exception of Botanigard® and Serenade®. Exposure to Botanigard® via contact at its MFRC caused 92% mortality after 11 weeks, while the 1/10 MFRC killed 46% of exposed workers. For Serenade®, topical contact and oral delivery via sugar water resulted in 88 and 100% worker mortality respectively. With lower concentrations (1/2, 1/5 and 1/10 MFRC) the toxicity decreased, but the effect depended on the route of exposure. In addition to lethal effects, nests were also evaluated for sublethal effects after treatment with the seven MCAs at their respective MFRCs over 11 weeks. In these bioassays, only Botanigard® and Serenade® gave rise to a significant (P < 0.05) decrease in drone production. Sublethal effects on foraging behaviour were also evaluated, and only Botanigard at its MFRC delivered via treated sugar water induced negative effects.

CONCLUSION: The results demonstrated that most of the MCAs tested can be considered safe for use in combination with B. terrestris, based on the International Organisation for Biological Control of Noxious Animals and Plants (IOBC) classification. However, some can be harmful, such as the biofungicide Serenade® and the bioinsecticide Botanigard®. Therefore, it is recommended that all should be tested before use in combination with pollinators. In this context, it is also advisable that these MCAs should be evaluated in more realistic field situations for the assessment of potentially deleterious effects on foraging behaviour. Copyright © 2009 Society of Chemical Industry
Using a selectivity index to evaluate logarithmic spraying in grass seed crops
Authors: Tind Tina , Mathiesen Tenna J , Jensen Jens E , Ritz Christian , Streibig Jens C
Published: August 2009

BACKGROUND: Grass seed crops are minor crops that cannot support the development of selective herbicides for grass weed control in grass seed crops. An option is to screen for selective herbicides with the use of logarithmic spraying technology. The aim of this paper is to assess selectivity of various herbicides in grass seed crops by using dose–response curves.

RESULTS: Six grass species were subjected to logarithmic spraying with 11 herbicides and with Poa pratensis L. as a weed. The ratio between the doses that caused 10% of damage to the crop and 90% of damage to the weed was used as a selectivity index. Compounds with selectivity indices above 2 can be safely used in a crop. The two ACCase herbicides clodinafop‐propargyl and fenoxaprop‐P‐ethyl and a mixture of the two ALS herbicides mesosulfuron and iodosulfuron could be used selectively to control P. pratensis in Festuca rubra L., although the selectivity indices in no instances were greater than the desired 2.0.

CONCLUSION: The logarithmic sprayer can be a rapid screening tool for identifying compounds with favourable selectivity indices. Good experimental design is needed to alleviate rates being systematically distributed and confounded with growth rate and soil fertility gradients. Copyright © 2009 Society of Chemical Industry
Epitaxial graphene: the material for graphene electronics
Authors: Sprinkle M. , Soukiassian P. , de Heer W. A. , Berger C. , Conrad E. H.
Published: August 2009

The search for an ideal graphene sheet has been a quest driving graphene research. While most research has focused on exfoliated graphene, intrinsic substrate interactions and mechanical disorder have precluded the observation of a number of graphene's expected physical properties in this material. The only graphene candidate that has demonstrated all the essential properties of an ideal sheet is multilayer graphene grown on the SiC(000$ \bar 1 $) surface. Its unique stacking allows nearly all the sheets in the stack to behave like isolated graphene, while the weak graphene‐graphene interaction prevents any significant doping or distortion in the band near the Fermi level. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Derivation of Functional Retinal Pigmented Epithelium from Induced Pluripotent Stem Cells
Authors: Buchholz David E. , Hikita Sherry T. , Rowland Teisha J. , Friedrich Amy M. , Hinman Cassidy R. , Johnson Lincoln V. , Clegg Dennis O.
Published: August 2009

Human induced pluripotent stem cells (iPSCs) have great promise for cellular therapy, but it is unclear if they have the same potential as human embryonic stem cells (hESCs) to differentiate into specialized cell types. Ocular cells such as the retinal pigmented epithelium (RPE) are of particular interest because they could be used to treat degenerative eye diseases, including age-related macular degeneration and retinitis pigmentosa. We show here that iPSCs generated using Oct4, Sox2, Nanog, and Lin28 can spontaneously differentiate into RPE cells, which can then be isolated and cultured to form highly differentiated RPE monolayers. RPE derived from iPSCs (iPS-RPE) were analyzed with respect to gene expression, protein expression, and rod outer segment phagocytosis, and compared with cultured fetal human RPE (fRPE) and RPE derived from hESCs (hESC-RPE). iPS-RPE expression of marker mRNAs was quantitatively similar to that of fRPE and hESC-RPE, and marker proteins were appropriately expressed and localized in polarized monolayers. Levels of rod outer segment phagocytosis by iPS-RPE, fRPE, and hESC-RPE were likewise similar and dependent on integrin αvβ5. This work shows that iPSCs can differentiate into functional RPE that are quantitatively similar to fRPE and hESC-RPE and further supports the finding that iPSCs are similar to hESCs in their differentiation potential.
Depot-Specific Differences in Adipogenic Progenitor Abundance and Proliferative Response to High-Fat Diet
Authors: Joe Aaron W.B. , Yi Lin , Even Yasmine , Vogl A. Wayne , Rossi Fabio M.V.
Published: August 2009

White adipose tissue (fat) is the primary organ for energy storage and its regulation has serious implications on human health. Excess fat tissue causes significant morbidity, and adipose tissue dysfunction caused by excessive adipocyte hypertrophy has been proposed to play a significant role in the pathogenesis of metabolic disease. Studies in both humans and animal models show that metabolic dysfunction is more closely associated with visceral than subcutaneous fat accumulation. Here, we show that in mice fed a high-fat diet, visceral fat (VAT) grows mostly by hypertrophy and subcutaneous fat (SAT) by hyperplasia, providing a rationale for the different effects of specific adipose depots on metabolic health. To address whether depot expansion is controlled at the level of stem/progenitor cells, we developed a strategy to prospectively identify adipogenic progenitors (APs) from both depots. Clonogenic assays and in vivo bromodeoxyuridine (BrdU) studies show that APs are eightfold more abundant in SAT than VAT, and that AP proliferation is significantly increased in SAT but not VAT in response to high-fat diet. Our results suggest that depot-specific differences in AP abundance and proliferation underlie whether a fat depot expands by hypertrophy or hyperplasia, and thus may have important implications on the development of metabolic disease. In addition, we provide the first evidence that dietary inputs can modulate the proliferation of adipogenic progenitors in adults.
Stem-Like Ovarian Cancer Cells Can Serve as Tumor Vascular Progenitors
Authors: Alvero Ayesha B. , Fu Han-Hsuan , Holmberg Jennie , Visintin Irene , Mor Liora , Marquina Carlos Cano , Oidtman Jessica , Silasi Dan-Arin , Mor Gil
Published: August 2009

Neovascularization is required for solid tumor maintenance, progression, and metastasis. The most described contribution of cancer cells in tumor neovascularization is the secretion of factors, which attract various cell types to establish a microenvironment that promotes blood vessel formation. The cancer stem cell hypothesis suggests that tumors are composed of cells that may share the differentiation capacity of normal stem cells. Similar to normal stem cells, cancer stem cells (CSCs) have the capacity to acquire different phenotypes. Thus, it is possible that CSCs have a bigger role in the process of tumor neovascularization. In this study, we show the capacity of a specific population of ovarian cancer cells with stem-like properties to give rise to xenograft tumors containing blood vessels, which are lined by human CD34+ cells. In addition, when cultured in high-density Matrigel, these cells mimic the behavior of normal endothelial cells and can form vessel-like structures in 24 hours. Microscopic analysis showed extensive branching and maturation of vessel-like structures in 7 days. Western blot and flow cytometry analysis showed that this process is accompanied by the acquisition of classic endothelial markers, CD34 and VE-cadherin. More importantly, we show that this process is vascular endothelial growth factor–independent, but IKKβ-dependent. Our findings suggest that anti-angiogenic therapies should take into consideration the inherent capacity of these cells to serve as vascular progenitors.
Confronting assumptions, biases, and stereotypes in preservice teachers' conceptualizations of science teaching through the use of book club
Authors: Mensah Felicia Moore
Published: August 2009

This study focuses on the structure and theoretical foundations of the book club for promoting multicultural understandings in science teacher education. The book club was defined as an informal, peer‐directed group discussion that met regularly to discuss an ethnographic, multicultural text regarding issues pertinent to science teaching and learning in urban classrooms. Twenty‐three preservice teachers (PSTs) enrolled in a 16‐week elementary science methods course at a large urban university participated in the study. From the qualitative analyses of PSTs' written reflections and researcher journal notes, five themes which emphasizeIndividual,Collaborative, andCollective learningare presented. These findings highlight how the book club structure and theoretical foundation fostered critical, reflective inquiry and served as a method for effecting ideological change which is needed in order to embrace issues of diversity in urban science education. Implications for science teacher education concerning the relevancy of pedagogical strategies, the use of multiple theoretical perspectives, and the book club as a strategy in teacher education and urban education are discussed. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 46: 1041–1066, 2009
Learning from and responding to students' questions: The authoritative and dialogic tension
Authors: Aguiar Orlando G. , Mortimer Eduardo F. , Scott Phil
Published: August 2009

In this study we present an analysis of classroom interactions initiated by students' wonderment questions. Our interest in such events arises from their potential to stimulate active intellectual engagement in classrooms, which can impact upon the subsequent development of the classroom discourse. In investigating this issue we shall address the following research question: How do student questions impact upon the teaching explanatory structure and modify the form of the ongoing classroom discourse, in selected science lessons? From data collected in a Brazilian secondary school we have selected three classroom episodes, with large differences in both the context in which the student's question emerges and in the communicative approach developed in response to it. The analysis, based on the framework proposed by Mortimer and Scott [Mortimer and Scott (2003). Meaning making in secondary science classrooms. Maidenhead: Open University Press], shows that questions made by students are important in providing feedback from students to the teacher, enabling adjustments to the teaching explanatory structure. These adjustments sometimes occur smoothly, at other times with major changes to the features of the classroom discourse, and elsewhere with misunderstanding and disagreement. The data also suggest the need to consider students' intentions and their active participation in the negotiation of both the content and structure of classroom discourse. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47:174–193, 2010
Developing a hypothetical multi‐dimensional learning progression for the nature of matter
Authors: Stevens Shawn Y. , Delgado César , Krajcik Joseph S.
Published: August 2009

We describe efforts toward the development of a hypothetical learning progression (HLP) for the growth of grade 7–14 students' models of the structure, behavior and properties of matter, as it relates to nanoscale science and engineering (NSE). This multi‐dimensional HLP, based on empirical research and standards documents, describes how students need to incorporate and connect ideas within and across their models of atomic structure, the electrical forces that govern interactions at the nano‐, molecular, and atomic scales, and information in the Periodic Table to explain a broad range of phenomena. We developed a progression from empirical data that characterizes how students currently develop their knowledge as part of the development and refinement of the HLP. We find that most students are currently at low levels in the progression, and do not perceive the connections across strands in the progression that are important for conceptual understanding. We suggest potential instructional strategies that may help students build organized and integrated knowledge structures to consolidate their understanding, ready them for new ideas in science, and help them construct understanding of emerging disciplines such as NSE, as well as traditional science disciplines. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47:687–715, 2010
Brief report: The KIDSCREEN follow‐up study on Health‐related Quality of Life (HRQoL) in Spanish children and adolescents. Pilot test and representativeness☆
Authors: Palacio‐Vieira J.A. , Villalonga‐Olives E. , Alonso J. , Valderas J.M. , Herdman M. , Espallargues M. , Berra S. , Rajmil L.
Published: August 2009

The Spanish KIDSCREEN follow‐up study reassessed the Spanish baseline sample (n = 840) of the European KIDSCREEN study 3 years later (2006). The aims of this paper were to describe the KIDSCREEN follow‐up study and the pilot test, and to analyze participation rates and representativeness. Instruments included the KIDSCREEN‐52 HRQoL measure and a set of scales including the possible explanatory variables. Focus groups and individual interviews were carried out in a pilot test. Participants were compared with non‐participants at baseline, and also with Eurostat census data. Twenty‐two out of 24 subjects were interviewed in the pilot test. Fifteen items needed to be modified after the pilot test. Participation rate reached 54% (n = 454). Participants (mean age = 12.71 years old) were on average 6 months younger than non‐participants (p = 0.03), and from more educated families. KIDSCREEN follow‐up instrumentation seems adequate for collecting factors with potential influence on HRQoL. Follow‐up respondents' representativeness seems to be acceptable.
Rhizospheric NO interacts with the acquisition of reduced N sources by the roots of European beech (Fagus sylvatica L.)
Authors: Simon Judy , Stoelken Gunda , Rienks Michael , Rennenberg Heinz
Published: August 2009

The gas phase of the soil plays an important role in plant growth and development. We investigated the effect of rhizospheric NO as a signalling compound for N uptake of beech roots. Following exposure to NO, ammonium and glutamine uptake into roots were determined using 15N‐labelling, and gene expression of selected transporters was analysed by quantitative real‐time PCR. Uptake of both N sources increased significantly with elevated NO concentration. However, with one exception, this increase was not reflected in up‐regulation of expression of the respective transporters.
Efficacy of wheat-based biscuits fortified with microcapsules containing ferrous sulfate and potassium iodate or a new hydrogen-reduced elemental iron: a randomised, double-blind, controlled trial in Kuwaiti women
Authors: Biebinger Ralf , Zimmermann Michael B. , Al-Hooti Suad N. , Al-Hamed Nawal , Al-Salem Ebtehal , Zafar Tasleem , Kabir Yearul , Al-Obaid I'nam , Petry Nicolai , Hurrell Richard F.
Published: August 2009

Adverse sensory changes prevent the addition of highly bioavailable ferrous sulfate (FeSO4) to most wheat flours. Poorly absorbable reduced Fe powders are commonly used. Encapsulation of FeSO4can overcome these sensory changes, but the particle size of commercial compounds is too large to be used by flour mills. The first objective of the study was to measure the efficacy in wheat flour of two newly developed Fe compounds, an H-reduced Fe powder (NutraFine™ RS; North America Höganäs High Alloys LLC, Johnstown, PA, USA) and small particle-sized (40 μm) encapsulated FeSO4. As a second objective, the microcapsules were evaluated as a vehicle for iodine fortification. A randomised, double-blind controlled intervention trial was conducted in Kuwaiti women (n279; aged 18–35 years) with low body Fe stores (serum ferritin (SF) < 25 μg/l) randomly assigned to one of three groups (20 mg Fe as NutraFine™ RS, 10 mg Fe as encapsulated FeSO4and 150 μg iodine, or no fortification Fe) who consumed wheat-based biscuits 5 d per week. At baseline and 22 weeks, Hb, SF, transferrin receptor, urinary iodine and body Fe stores were measured. Relative to control, mean SF in the encapsulated FeSO4group increased by 88 % (P < 0·001) and body Fe stores increased from − 0·96 to 2·24 mg/kg body weight (P < 0·001), while NutraFine™ RS did not significantly increase SF or body Fe stores. The median urinary iodine concentration increased from 140 to 213 μg/l (P < 0·01). NutraFine™ RS added at double the amount of Fe as FeSO4was not efficacious in improving Fe status. The newly developed microcapsules were highly efficacious in improving both Fe stores and iodine status.
Water-wave trapping by floating circular cylinders
Authors: PORTER R. , EVANS D. V.
Published: August 2009

Under the assumptions of the linearized theory of small-amplitude water waves, it is proved that plane waves, normally incident upon a semi-immersed cylinder of uniform circular cross-section floating freely on the surface of a fluid of infinite depth, are capable of being totally reflected. Numerically, this is shown to occur at a single non-dimensional frequency. This remarkable result is used to construct examples of motion-trapped modes, involving pairs of freely floating cylinders moving either in phase or out of phase. The former case is equivalent to having a motion-trapped mode for a single such cylinder next to a rigid vertical wall. In the latter out-of-phase case, the pair of cylinders move as if they form the wetted sections of a single rigidly connected catamaran structure.
Turbulent transport mechanisms in oscillating bubble plumes
Authors: SIMIANO MARCO , LAKEHAL D. , LANCE M. , YADIGAROGLU G.
Published: August 2009

The detailed investigation of an unstable meandering bubble plume created in a 2-m-diameter vessel with a water depth of 1.5 m is reported for void fractions up to 4% and bubble size of the order of 2.5 mm. Simultaneous particle image velocity (PIV) measurements of bubble and liquid velocities and video recordings of the projection of the plume on two vertical perpendicular planes were produced in order to characterize the state of the plume by the location of its centreline and its equivalent diameter. The data were conditionally ensemble averaged using only PIV sets corresponding to plume states in a range as narrow as possible, separating the small-scale fluctuations of the flow from the large-scale motions, namely plume meandering and instantaneous cross-sectional area fluctuations. Meandering produces an apparent spreading of the average plume velocity and void fraction profiles that were shown to remain self-similar in the instantaneous plume cross-section. Differences between the true local time-average relative velocities and the difference of the averaged phase velocities were measured; the complex variation of the relative velocity was explained by the effects of passing vortices and by the fact that the bubbles do not reach an equilibrium velocity as they migrate radially, producing momentum exchanges between high- and low-velocity regions. Local entrainment effects decrease with larger plume diameters, contradicting the classical dependence of entrainment on the time-averaged plume diameter. Small plume diameters tend to trigger ‘entrainment eddies’ that promote the inward-flow motion. The global turbulent kinetic energy was found to be dominated by the vertical stresses. Conditional averages according to the plume diameter showed that the large-scale motions did not affect the instantaneous turbulent kinetic energy distribution in the plume, suggesting that large scales and small scales are not correlated. With conditional averaging, meandering was a minor effect on the global kinetic energy and the Reynolds stresses. In contrast, plume diameter fluctuations produce a substantial effect on these quantities.
Evolution and breaking of parametrically forced capillary waves in a circular cylinder
Authors: PUTHENVEETTIL BABURAJ A. , HOPFINGER E. J.
Published: August 2009

We present results on parametrically forced capillary waves in a circular cylinder, obtained in the limit of large fluid depth, using two low-viscosity liquids whose surface tensions differ by an order of magnitude. The evolution of the wave patterns from the instability to the wave-breaking threshold is investigated in a forcing frequency range (f= ω/2π = 25–100 Hz) that is around the crossover frequency (ωot) from gravity to capillary waves (ωot/2≤ω/2≤4ωot). As expected, near the instability threshold the wave pattern depends on the container geometry, but as the forcing amplitude is increased the wave pattern becomes random, and the wall effects are insignificant. Near breaking, the distribution of random wavelengths can be fitted by a Gaussian. A new gravity–capillary scaling is introduced that is more appropriate, than the usual viscous scaling, for low-viscosity fluids and forcing frequencies <103Hz. In terms of these scales, a criterion is derived to predict the crossover from capillary- to gravity-dominated breaking. A wave-breaking model is developed that gives the relation between the container and the wave accelerations in agreement with experiments. The measured drop size distribution of the ejected drops above the breaking threshold is well approximated by a gamma distribution. The mean drop diameter is proportional to the wavelength determined from the dispersion relation; this wavelength is also close to the most likely wavelength of the random waves at drop ejection. The dimensionless drop ejection rate is shown to have a cubic power law dependence on the dimensionless excess acceleration ε′dan inertial–gravitational ligament formation model is consistent with such a power law.
An experimental investigation of incipient spilling breakers
Authors: DIORIO J. D. , LIU X. , DUNCAN J. H.
Published: August 2009

In the present paper, the profiles of incipient spilling breaking waves with wavelengths ranging from 10 to 120cm were studied experimentally in clean water. Short-wavelength breakers were generated by wind, while longer-wavelength breakers were generated by a mechanical wavemaker, using either a dispersive focusing or a sideband instability mechanism. The crest profiles of these waves were measured with a high-speed cinematic laser-induced fluorescence technique. For all the wave conditions reported herein, wave breaking was initiated with a capillary-ripple pattern as described in Duncan et al. (J. Fluid Mech., vol. 379, 1999, pp. 191–222). In the present paper, it is shown that at incipient breaking the crest shape is self-similar with two geometrical parameters that depend only on the slope of a particular point on the front face of the gravity wave. The scaling relationships appear to be universal for the range of wavelengths studied herein and hold for waves generated by mechanical wavemakers and by wind. The slope measure is found to be dependent on the wave phase speed and the rate of growth of the crest height prior to incipient breaking.
Influence of slip on the dynamics of two-dimensional wakes
Authors: LEGENDRE DOMINIQUE , LAUGA ERIC , MAGNAUDET JACQUES
Published: August 2009

We study numerically the two-dimensional flow past a circular cylinder as a prototypical transitional flow, and investigate the influence of a generic slip boundary condition on the wake dynamics. We show that slip significantly delays the onset of recirculation and shedding in the wake behind the cylinder. As expected, the drag on the cylinder decreases with slip, with an increased drag sensitivity for large Reynolds numbers. We also show that past the critical shedding Reynolds number, slip decreases the vorticity intensity in the wake, as well as the lift forces on the cylinder, but increases the shedding frequency. We further provide evidence that the shedding transition can be interpreted as a critical accumulation of surface vorticity, similarly to related studies on wake instability of axisymmetric bodies. Finally, we propose that our results could be used as a passive method to infer the effective friction properties of slipping surfaces.
Interaction between two laser-induced cavitation bubbles in a quasi-two-dimensional geometry
Authors: QUINTO-SU PEDRO A. , OHL CLAUS-DIETER
Published: August 2009

We report on experimental and numerical studies of pairs of cavitation bubbles growing and collapsing close to each other in a narrow gap. The bubbles are generated with a pulsed and focused laser in a liquid-filled gap of 15 μm height; during their lifetime which is shorter than 14 μs they expand to a maximum radius of up to Rmax = 38 μm. Their motion is recorded with high-speed photography at up to 500000 frames s−1. The separation at which equally sized bubbles are created, d, is varied from d = 46–140 μm which results into a non-dimensional stand-off distance, γ = d/(2Rmax), from 0.65 to 2. For large separation the bubbles shrink almost radially symmetric; for smaller separation the bubbles repulse each other during expansion and during collapse move towards each other. At closer distances we find a flattening of the proximal bubbles walls. Interestingly, due to the short lifetime of the bubbles (≤14 μs), the radial and centroidal motion can be modelled successfully with a two-dimensional potential flow ansatz, i.e. neglecting viscosity. We derive the equations for arbitrary configurations of two-dimensional bubbles. The good agreement between model and experiments supports that the fluid dynamics is essentially a potential flow for the experimental conditions of this study. The interaction force (secondary Bjerknes force) is long ranged dropping off only with 1/d as compared to previously studied three-dimensional geometries where the force is proportional to 1/d2.
Mean temperature profiles in turbulent Rayleigh–Bénard convection of water
Authors: SHISHKINA OLGA , THESS ANDRÉ
Published: August 2009

We report an investigation of temperature profiles in turbulent Rayleigh–Bénard convection of water based on direct numerical simulations (DNS) for a cylindrical cell with unit aspect ratio for the same Prandtl number Pr and similar Rayleigh numbers Ra as used in recent high-precision measurements by Funfschilling et al. (J. Fluid Mech., vol. 536, 2005, p. 145). The Nusselt numbers Nu computed for Pr = 4.38 and Ra = 108, 3 × 108, 5 × 108, 8 × 108 and 109 are found to be in excellent agreement with the experimental data corrected for finite thermal conductivity of the walls. Based on this successful validation of the numerical approach, the DNS data are used to extract vertical profiles of the mean temperature. We find that near the heating and cooling plates the non-dimensional temperature profiles Θ(y) (where y is the non-dimensional vertical coordinate), obey neither a logarithmic nor a power law. Moreover, we demonstrate that the Prandtl–Blasius boundary layer theory cannot predict the shape of the temperature profile with an error less than 7.9% within the thermal boundary layers (TBLs). We further show that the profiles can be approximated by a universal stretched exponential of the form Θ(y) ≈ 1 − exp(−y − 0.5y2) with an absolute error less than 1.1% within the TBLs and 5.5% in the whole Rayleigh cell. Finally, we provide more accurate analytical approximations of the profiles involving higher order polynomials in the approximation.
Particle-wall collision in a viscoelastic fluid
Authors: ARDEKANI A. M. , JOSEPH D. D. , DUNN-RANKIN D. , RANGEL R. H.
Published: August 2009

In this study, we present experimental results on particle-wall collision in viscoelastic fluids. A sphere is released in a tank filled with poly(ethylene-oxide) (PEO) mixed with water with varying concentrations up to 1.5%. The effect of Stokes and Deborah numbers on the rebound velocity of a spherical particle colliding onto a wall is considered. It has been observed that the slope at which the coefficient of restitution increases with Stokes number is smaller for higher Deborah numbers. Higher rebound occurs for higher PEO concentration at the same stokes number. However, the results for the coefficient of restitution in polymeric liquids can be collapsed together with the Newtonian fluid behaviour if one defines the Stokes number based on the local strain rate.
Length–depth relations of Enchelyopus cimbrius fourbeard rockling (Gadiformes: Phycidae) from the southern Gulf of St Lawrence and Cabot Strait in relation to abiotic factors
Authors: Aubry Eliane , Methven D.A. , Hurlbut Tom
Published: August 2009

Research vessel survey data collected by Fisheries and Oceans Canada in the southern Gulf of St Lawrence (1971–2002) and Cabot Strait (1994–1997) were analysed to determine if Enchelyopus cimbrius the fourbeard rockling, distributed itself with larger individuals occurring in deeper water. A positive size–depth relationship was first observed for the European plaice, Pleuronectes platessa in the North Sea and has been reported for other fish. Positive relationships were found between the total length of E. cimbrius and depths where it occurred in this study. However, the biological relationship was not significant since the linear regression slopes were very weak, explaining less than approximately five per cent of the variance observed. Data were analysed further to determine the water depth, temperature and salinity ranges where the fourbeard rockling was most abundant. Enchelyopus cimbrius occurred throughout the depth-ranges sampled with highest catches occurring at 25–50 m (southern Gulf of St Lawrence) and deeper than 200 m (southern Gulf of St Lawrence and Cabot Strait). Low catches at intermediate depths (~50–100 m) in the southern Gulf of St Lawrence may have been due to the lack of suitable mud substrate and colder bottom temperatures in the Magdalen Shallows, a large central region of the southern Gulf. Enchelyopus cimbrius was mostly caught at relatively narrow temperature and salinity ranges of 4–6°C and 34–34.9 ppt in both regions, and only occurred in areas with a mud substratum, predominantly in the eastern Northumberland Strait, Baie des Chaleurs and in the deeper water of the Cape Breton Trough, Laurentian Channel and Cabot Strait. Enchelyopus cimbrius was caught throughout the day and night, contradicting a previous study that characterized it as being nocturnal in shallow coastal waters off Newfoundland.
Reproductive biology of the banded guitarfish, Zapteryx exasperata, from the Gulf of California, México
Authors: Blanco-Parra María-Del-Pilar , Márquez-Farías J. Fernando , Galván-Magaña Felipe
Published: August 2009

The banded guitarfish, Zapteryx exasperata, is a common species in the artisanal elasmobranch fisheries in the Gulf of California. Fishery-derived specimens were examined to determine critical aspects of the reproductive biology of this poorly known group of rays. Two functional testes and ovaries were found in males and females respectively. Median size at maturity (L50%) for males was 64 cm total length (TL) and for females 69 cm TL. Average length of gravid females was 78.8±3.8 cm TL. Histological analysis showed no evidence of sperm storage in the oviducal gland. Gestation was estimated to occur over a five to six month period (February–July) and was concurrent with vitellogenesis. Mean uterine fecundity was estimated as 7 (range 2–13, SD. = 3). The sex-ratio of embryos was 1:1. The reproductive cycle for Z. exasperata from the Gulf of California was estimated to last one year with parturition, ovulation and copulation occurring during the summer months. Differences found in the reproductive cycle of Z. exasperata between the Gulf of California and the west coast of Baja California could have implications in the future management plans for this fishery in the Gulf of California.
Childhood exposure to sexual abuse and partnership outcomes at age 30
Authors: Friesen M. D. , Woodward L. J. , Horwood L. J. , Fergusson D. M.
Published: August 2009

Background

In this study, 30-year longitudinal data from the Christchurch Health and Development Study (CHDS) were used to examine the associations between childhood exposure to sexual abuse and intimate relationship outcomes at age 30. In addition, a broad range of early childhood and family confounding factors were tested, and the role of intervening factors from adolescence was explored.

Method

The investigation analyzed data from a birth cohort of over 900 New Zealand adults studied to the age of 30. At ages 18 and 21 cohort members reported on any exposure to sexual abuse prior to age 16. This information, along with prospective data gathered in childhood and adolescence, was used to predict partnership outcomes at age 30.

Results

After adjustment for early childhood and family factors, exposure to more severe forms of childhood sexual abuse (CSA) was associated with earlier and more frequent cohabitation, higher rates of perpetrated interpartner violence (IPV), and early parenthood, lower relationship satisfaction and investment. Several factors from adolescence partially or fully mediated these associations, notably a history of early consensual sexual intercourse, higher number of sexual partnerships, substance abuse problems, and self-esteem. After adjustment for intervening factors, exposure to CSA remained significantly associated with IPV.

Conclusions

The findings support a causal chain process, whereby early childhood and family factors place some individuals at risk for CSA. The extent of CSA exposure is related to adolescent risk taking, which in turn leads to early and more frequent cohabitation, risk of IPV, and lower relationship satisfaction and investment.
The Deification of The State
Authors: Friedrich C. J.
Published: August 2009

It is a Common heritage of English and American liberals to denounce state absolutism, to deny it as regimentation, paternalism, etc. etc. Indeed, Englishmen and Americans have always been inclined to adopt a condescending attitude towards other traditions which seemed to exalt state power. French and German, Russian and Italian tendencies have in turn been pictured as “naturally” inclined toward state “absolutism,” and when anyone in rebuttal mentioned Hobbes or Bentham or Austin, the “exceptional” position of these thinkers has been emphasized. Still, can there be any question that the idea of the state as an ultimate source of authority has been as strong in Great Britain as anywhere? For reasons which will become plainer in the course of the argument, English-writing thinkers have accordingly been in the vanguard of those who sought to construct the “state” as the “highest” of all human communities, thus following out the Aristotelian heritage. In spite of all the titter-tatter about national character, muddling through and the rest, the fact remains that Britain has provided us with the most radical, deep-laid expositions of an “absolute” state. This much admitted, one might add that the limited state also has found eloquent and epoch-making exponents in English-speaking lands. In short, the whole gamut of modern political philosophy has been most thoroughly expounded in English.
Parties and the Common Good
Authors: Adler Mortimer
Published: August 2009

This paper has a twofold intention.

The first is to discuss the problem of political parties, — their justification and status, — in a society which requires political democracy as the set of political institutions appropriate for the government of men living under modern social and economic conditions. (By these modern conditions I mean such things as the economic forms of production and distribution in the industrial era; the organization of labor in relation to economic enterprise; the intensity and extensity of communication among men living in geographical separation and, consequently, the physical enlargement of the civic association; the approximation to universal education; the spread of literacy, etc.) There are two points to be noted here:

(1) That modern society is or tends toward a democracy in its physical and economic conditions, whether in a given instance its political forms are outwardly democratic, as in France, England and the United States, or anti-democratic, as in Italy, Germany and Russia.

(a) Not only does Russia publicize its claim to being democratic and make constitutional efforts in that direction which are, of course, at once vitiated by the persistence of its totalitarian regime; but even Germany and Italy give an appearance of democracy, — though they abominate the thought and word, — an appearance which is a reverse and distorted image. Thus, by the pressure of propaganda and the exercise of brutal force, the rulers of Germany and Italy try to make it appear that they have a mandate from the people for their policies.
Prelude To Democracy—Part Two
Authors: Briefs Goetz
Published: August 2009

Communitarian forms of life are the basic forms in which a people lives. Only in them does man realize to the fullest his being a person—in fact it is only in communitarian forms that he grows to the status of a person. Man's fundamental mode of being is comunio, namely of persons. Such comunio materializes in family life, in friendship, in neighborhood, in religious life, in certain forms of vocational collaboration. Beside these fundamental forms man builds himself free-willed associations which do not engage his personality to its deepest and fullest extent, as e.g. trade unions, corporations, societies and associations for cultural, scientific, recreational purposes. For want of a better term we call them in contradistinction to the other forms societarian forms, in following the terminology of F. Toennies in his book Gemeinschaft und Gesellschaft (Community and Society). Both these forms develop in a people and aid in constituting a people. However, the communitarian forms are basic and therefore of greater importance for the totality of a people's life, its political institutions included.
The European Crisis and the Downfall of the French Republic
Authors: Simon Yves R.
Published: August 2009

Numerous books and articles dealing with the disaster of France have already been published in this country. Most of them are not limited to the recording of facts; their main concern is to explain this bewildering event: the sudden collapse, after so brief a struggle, of such a power as the French Republic. Although the explanations differ largely from one another, on the ground of a diversity of experiences, sources, political preferences and prejudices, most writers have commonly a tendency to emphasize the part played, in France's defeat, by the individual mistakes of military chiefs and political leaders.
Checks with Balances
Authors: Kerwin Jerome G.
Published: August 2009

Let us begin with a frank acknowledgment: the American fondness for new structural forms is both virtue and fault politically. Since our proneness to frequent alteration of governmental structures engenders a certain self-distrust, we place upon our actions the restraint found in our tortuous constitutional amending process. Still hankering for change, however, and finding the amending process too rigid, we bend and twist the meaning of the fundamental law with amazing casuistry. The defect as well as the virtue of this practis obvious. On the one hand we change a structure before it has been thoroughly tested, having mistakenly hoped, in the first place, to achieve complete reform by structure and law alone. On the other hand, no one can deny that this willingness to change and experiment with new forms and institutions has contributed to governmental and political progress. City manager government, popular initiation of legislation, direct nomination of party candidates, the organization, control and operation of regional areas like the T.V.A. and the Port of New York Authority, and many recent creations in governmental structure and operations— all these, despite certain difficulties and weaknesses, have contributed to the general advancement of the theory and practice of government. Disappointment, of course, has often followed reform. Too much has been promised, and performance has fallen short of expectations. Bitter disillusionment has often brought reaction. And yet, no one can seriously maintain that in the long run we have not progressed. It is true that in the late nineteenth and early twentieth centuries, the pressure for regulation and control of utilities did not result in a wholesale reform of big business and its practices. Yet, while big business might have been forced to adopt methods less brutal and less careless of the public interest, it was at least kept from returning to its older “public-be-damned” attitude. If some few reforms have been totally ineffective, most of them have been a decided improvement on the older, less efficient, less popularly responsive systems which they replaced.
The American Catholic Minority in the Later Nineteenth Century
Authors: McAvoy Thomas T.
Published: August 2009

The factors that caused the Roman authorities to insist on a Plenary Council of the American Bishops in 1884 have not been sufficiently explained. Perhaps the role of the American prelates in opposing the opportuneness of the definition of the doctrine of infallibility had some influence. Undoubtedly the reports of the bishops in their ad limina visits to Rome did little to subdue any fears that may have arisen. The frequent appeals of recalcitrant clergymen against their bishops were going directly to Rome because there was no intermediate court. The Instruction of 1878 makes this quite clear. Rome had shown its dissatisfaction with the condition of Catholic education by its interrogatory and its Instruction of 1875. The renewed condemnation of the Fenians had some American effects; and the renewed condemnation of the Masons with applications to certain other American social organizations indicated that all was not well in the social conditions of Catholics in the United States. Had the prelates in Rome understood American democracy and American conditions they would have had to have been much better informed than most Europeans in the nineteenth century. America was to Europe a land of great physical possibility, but a land without any great culture or religious accomplishments. Even European liberals did not understand the manhood suffrage of American democracy. The Catholic leaders of southern Europe, so generally aligned with conservative and monarchist parties, could have little understanding of American democracy in the religious sphere. In Rome where the hierarchical arrangement had not been fully dissociated from monarchical government and where Roman law with its insistence on the union of Church and State was the basis of most political thought, even the most sympathetic seemed to have some misgivings about the manifest loyalty of the American Catholics to the Holy See.
The Ruling Bureaucracy of Oriental Despotism: A Phenomenon That Paralyzed Marx
Authors: Wittfogel Karl A.
Published: August 2009

When Marx, in 1849, took up permanent residence in London, he devoted himself once more—and with great thoroughness—to the study of the classical economists. And he accepted, along with many other ideas of Adam Smith, Richard Jones, and John Suart Mill, their conviction that, outside and independent of the Western world, there existed a specific institutional conformation, which they called Asiatic or Oriental society.