bluuebunny/crossref_metadata_2025 huggingface dataset:
Canonical WNT signaling during kidney development
Authors: Iglesias Diana M. , Hueber Pierre-Alain , Chu LeeLee , Campbell Robert , Patenaude Anne-Marie , Dziarmaga Alison J. , Quinlan Jacklyn , Mohamed Othman , Dufort Daniel , Goodyer Paul R.
Published: May 2007

The canonical WNT signaling pathway plays a crucial role in patterning of the embryo during development, but little is known about the specific developmental events which are under WNT control. To understand more about how the WNT pathway orchestrates mammalian organogenesis, we studied the canonical β-catenin-mediated WNT signaling pathway in kidneys of mice bearing a β-catenin-responsive TCF/βGal reporter transgene. In metanephric kidney, intense canonical WNT signaling was evident in epithelia of the branching ureteric bud and in nephrogenic mesenchyme during its transition into renal tubules. WNT signaling activity is rapidly downregulated in maturing nephrons and becomes undetectable in postnatal kidney. Sites of TCF/βGal activity are in proximity to the known sites of renal WNT2b and WNT4 expression, and these WNTs stimulate TCF reporter activity in kidney cell lines derived from ureteric bud and metanephric mesenchyme lineages. When fetal kidney explants from HoxB7/GFP mice were exposed to the canonical WNT signaling pathway inhibitor, Dickkopf-1, arborization of the ureteric bud was significantly reduced. We conclude that restricted zones of intense canonical WNT signaling drive branching nephrogenesis in fetal kidney.
The apneic threshold during non-REM sleep in dogs: sensitivity of carotid body vs. central chemoreceptors
Authors: Smith C. A. , Chenuel B. J. , Henderson K. S. , Dempsey J. A.
Published: May 2007

The relative importance of peripheral vs. central chemoreceptors in causing apnea/unstable breathing during sleep is unresolved. This has never been tested in an unanesthetized preparation with intact carotid bodies. We studied three unanesthetized dogs during normal sleep in a preparation in which intact carotid body chemoreceptors could be reversibly isolated from the systemic circulation and perfused. Apneic thresholds and the CO2 reserve (end-tidal Pco2 eupneic − end-tidal Pco2 apneic threshold) were determined using a pressure support ventilation technique. Dogs were studied when both central and peripheral chemoreceptors sensed transient hypocapnia induced by the pressure support ventilation and again with carotid body isolation such that only the central chemoreceptors sensed the hypocapnia. We observed that the CO2 reserve was ≅4.5 Torr when the carotid chemoreceptors sensed the transient hypocapnia but more than doubled (>9 Torr) when only the central chemoreceptors sensed hypocapnia. Furthermore, the expiratory time prolongations observed when only central chemoreceptors were exposed to hypocapnia differed from those obtained when both the central and peripheral chemoreceptors sensed the hypocapnia in that they 1) were substantially shorter for a given reduction in end-tidal Pco2, 2) showed no stimulus: response relationship with increasing hypocapnia, and 3) often occurred at a time (>45 s) beyond the latency expected for the central chemoreceptors. These findings agree with those previously obtained using an identical pressure support ventilation protocol in carotid body-denervated sleeping dogs (Nakayama H, Smith CA, Rodman JR, Skatrud JB, Dempsey JA. J Appl Physiol 94: 155–164, 2003). We conclude that hypocapnia sensed at the carotid body chemoreceptor is required for the initiation of apnea following a transient ventilatory overshoot in non-rapid eye movement sleep.
Firing Dynamics of Cerebellar Purkinje Cells
Authors: Fernandez Fernando R. , Engbers Jordan D. T. , Turner Ray W.
Published: May 2007

Knowledge of intrinsic neuronal firing dynamics is a critical first step to establishing an accurate biophysical model of any neuron. In this study we examined cerebellar Purkinje cells to determine the bifurcations likely to underlie firing dynamics within a biophysically realistic and experimentally supported model. We show that Purkinje cell dynamics are consistent with a system undergoing a saddle-node bifurcation of fixed points in the transition from rest to firing and a saddle homoclinic bifurcation from firing to rest. Our analyses account for numerous observed Purkinje cell firing properties that include bistability, plateau potentials, specific aspects of the frequency–current ( F– I) relationship, first spike latency, and the ability for climbing fiber input to induce state transitions in the bistable regime. We also experimentally confirm new properties predicted from our model and analysis that include the presence of a depolarizing afterpotential (DAP), the ability to fire at low frequencies (<50 Hz) and with a high gain in the F– I relationship, and a bistable region limited to low-frequency firing. Purkinje cell dynamics, including bistability, prove to arise from numerous biophysical factors that include the DAP, fast refractory dynamics, and a long membrane time constant. A hyperpolarizing activated cation current ( IH) is shown not to be directly involved in establishing bistable dynamics but rather reduces the range for bistability. A combined electrophysiological and modeling approach thus accounts for several properties of Purkinje cells, providing a firm basis from which to assess Purkinje cell output patterns.
Mechanism of Spontaneous and Receptor-Controlled Electrical Activity in Pituitary Somatotrophs: Experiments and Theory
Authors: Tsaneva-Atanasova Krasimira , Sherman Arthur , van Goor Frederick , Stojilkovic Stanko S.
Published: May 2007

Cultured pituitary somatotrophs release growth hormone in response to spontaneous Ca2+ entry through voltage-gated calcium channels (VGCCs) that is governed by plateau-bursting electrical activity and is regulated by several neurohormones, including GH-releasing hormone (GHRH) and somatostatin. Here we combine experiments and theory to clarify the mechanisms underlying spontaneous and receptor-controlled electrical activity. Experiments support a role of a Na+-conducting and tetrodotoxin-insensitive channel in controlling spontaneous and GHRH-stimulated pacemaking, the latter in a cAMP-dependent manner; an opposing role of spontaneously active inwardly rectifying K+ ( Kir) channels and G-protein-regulated Kir channels in somatostatin-mediated inhibition of pacemaking; as well as a role of VGCCs in spiking and large conductance (BK-type) Ca2+-activated K+ channels in plateau bursting. The mathematical model is compatible with a wide variety of experimental data involving pharmacology and extracellular ion substitution and supports the importance of constitutively active tetrodotoxin-insensitive Na+ and Kir channels in maintaining spontaneous pacemaking in pituitary somatotrophs. The model also suggests that these channels are involved in the up- and downregulation of electrical activity by GHRH and somatostatin. In the model, the plateau bursting is controlled by two functional populations of BK channels, characterized by distance from the VGCCs. The rapid activation of the proximal BK channels is critical for the establishment of the plateau, whereas slow recruitment of the distal BK channels terminates the plateau.
Nociceptive Craniofacial Muscle Primary Afferent Neurons Synapse in Both the Rostral and Caudal Brain Stem
Authors: Dessem Dean , Moritani Masayuki , Ambalavanar Ranjinidevi
Published: May 2007

Limited information is available on muscle afferent neurons with fine fibers despite their presumed participation in musculoskeletal disorders, including temporomandibular disorders. To study these neurons, intracellular recordings were made from the central axons of slowly conducting muscle afferent neurons in anesthetized rats. After intraaxonal impalement, axons were characterized by masseter nerve stimulation, receptive field testing, muscle stretching and intramuscular injection of hypertonic saline. Intracellular recordings were made from 310 axons (conduction velocity: 6.5–60M/s, mean = 27.3M/s; following frequency: 27–250 Hz, mean = 110Hz). No neurons responded to cutaneous palpation or muscle stretching. Some axons ( n = 34) were intracellularly stained with biotinamide. These neurons were classified as group II/III noxious mechanoreceptors because their mechanical threshold exceeded 15 mN, and conduction velocities ranged from 12 to 40.2M/s (mean = 25.3M/s). Two morphological types were recognized by using an object-based, three-dimensional colocalization methodology to locate synapses. One type (IIIHTMVp-Vc) possessed axon collaterals that emerged along the entire main axon and synapsed in the trigeminal principal sensory nucleus and spinal trigeminal subnuclei oralis (Vo), interpolaris (Vi), and caudalis (Vc). A second type (IIIHTMVo-Vc) possessed axon collaterals that synapsed only in caudal Vo, Vi, and Vc. Our previous studies show that muscle spindle afferent neurons are activated by innocuous stimuli and synapse in the rostral and caudal brain stem; here we demonstrate that nociceptive muscle mechanoreceptor afferent axons also synapse in rostral and caudal brain stem regions. Traditional dogma asserts that the most rostral trigeminal sensory complex exclusively processes innocuous somatosensory information, whereas caudal portions receive nociceptive sensory input; the data reported here do not support this paradigm.
Methods for Voltage-Sensitive Dye Imaging of Rat Cortical Activity With High Signal-to-Noise Ratio
Authors: Lippert Michael T. , Takagaki Kentaroh , Xu Weifeng , Huang Xiaoying , Wu Jian-Young
Published: May 2007

We describe methods to achieve high sensitivity in voltage-sensitive dye (VSD) imaging from rat barrel and visual cortices in vivo with the use of a blue dye RH1691 and a high dynamic range imaging device (photodiode array). With an improved staining protocol and an off-line procedure to remove pulsation artifact, the sensitivity of VSD recording is comparable with that of local field potential recording from the same location. With this sensitivity, one can record from ∼500 individual detectors, each covering an area of cortical tissue 160 μm in diameter (total imaging field ∼4 mm in diameter) and a temporal resolution of 1,600 frames/s, without multiple-trial averaging. We can record 80–100 trials of intermittent 10-s trials from each imaging field before the VSD signal reduces to one half of its initial amplitude because of bleaching and wash-out. Taken together, the methods described in this report provide a useful tool for visualizing evoked and spontaneous waves from rodent cortex.
Models for Master-Slave Clock Distribution Networks with Third-Order Phase-Locked Loops
Authors: Piqueira José Roberto Castilho , de Carvalho Freschi Marcela
Published: May 2007

The purpose of this work is to study the processing and transmission of clock signals in networks of geographically distributed nodes, in order to derive conditions for frequency and phase synchronization between the nodes. The focus is on the master-slave architecture, which presents a priority scheme of clock distribution. One-way master-slave (OWMS ) and two-way master-slave (TWMS) chains are studied, considering that the slave nodes are third-order phase-locked loops (PLLs). Third-order PLLs are chosen to improve the transient response but, if their parameters are not well adjusted, stability problems and chaotic behaviors appear, restricting the lock-in range of the network. Lock-in range for third-order PLLs with Sallen-Key filter is determined and it is verified whether this range is reduced when the PLLs are connected to a network. Numerical experiments show how chain size changes the lock-in ranges and the acquisition times.
A Fast Reconstruction Algorithm for Fluorescence Optical Diffusion Tomography Based on Preiteration
Authors: Song Xiaolei , Xiong Xiaoyun , Bai Jing
Published: May 2007

Fluorescence optical diffusion tomography in the near‐infrared (NIR) bandwidth is considered to be one of the most promising ways for noninvasive molecular‐based imaging. Many reconstructive approaches to it utilize iterative methods for data inversion. However, they are time‐consuming and they are far from meeting the real‐time imaging demands. In this work, a fast preiteration algorithm based on the generalized inverse matrix is proposed. This method needs only one step of matrix‐vector multiplication online, by pushing the iteration process to be executed offline. In the preiteration process, the second‐order iterative format is employed to exponentially accelerate the convergence. Simulations based on an analytical diffusion model show that the distribution of fluorescent yield can be well estimated by this algorithm and the reconstructed speed is remarkably increased.
New Perspectives on Thiamine Catalysis: From Enzymic to Biomimetic Catalysis
Authors: Stamatis A. , Malandrinos G. , Louloudi M. , Hadjiliadis N.
Published: May 2007

This paper is a brief review of the detailed mechanism of action of thiamine enzymes, based on metal complexes of bivalent transition and post-transition metals of model compounds, thiamine derivatives, synthesized and characterized with spectroscopic techniques and X-ray crystal structure determinations. It is proposed that the enzymatic reaction is initiated with a V conformation of thiamine pyrophosphate, imposed by the enzymic environment. Thiamine pyrophosphate is linked with the proteinic substrate through its pyrophosphate oxygens. In the course of the reaction, the formation of the “active aldehyde” intermediate imposes the S conformation to thiamine, while a bivalent metal ion may be linked through the N1' site of the molecule, at this stage. Finally, the immobilization of thiamine and derivatives on silica has a dramatic effect on the decarboxylation of pyruvic acid, reducing the time of its conversion to acetaldehyde from 330 minutes for the homogeneous system to less than 5 minutes in the heterogenous system.
A Self-Adaptive Method for Solving a System of Nonlinear Variational Inequalities
Authors: Shi Chaofeng
Published: May 2007

The system of nonlinear variational inequalities (SNVI) is a useful generalization of variational inequalities. Verma (2001) suggested and analyzed an iterative method for solving SNVI. In this paper, we present a new self-adaptive method, whose computation cost is less than that of Verma's method. The convergence of the new method is proved under the same assumptions as Verma's method. Some preliminary computational results are given to illustrate the efficiency of the proposed method.
The Many Facets of SDF-1α, CXCR4 Agonists and Antagonists on Hematopoietic Progenitor Cells
Authors: Faber Anne , Roderburg Christoph , Wein Frederik , Saffrich Rainer , Seckinger Anja , Horsch Kerstin , Diehlmann Anke , Wong Donald , Bridger Gary , Eckstein Volker , Ho Anthony D. , Wagner Wolfgang
Published: May 2007

Stromal cell-derived factor-1alpha (SDF-1α) has pleiotropic effects on hematopoietic progenitor cells (HPCs). We have monitored podia formation, migration, proliferation, and cell-cell adhesion of human HPC under the influence of SDF-1α, a peptide agonist of CXCR4 (CTCE-0214), a peptide antagonist (CTCE-9908), and a nonpeptide antagonist (AMD3100). Whereas SDF-1αinduced migration ofCD34+cells in a dose-dependent manner, CTCE-0214, CTCE-9908, and AMD3100 did not induce chemotaxis in this concentration range albeit the peptides CTCE-0214 and CTCE-9908 increased podia formation. Cell-cell adhesion of HPC to human mesenchymal stromal cells was impaired by the addition of SDF-1α, CTCE-0214, and AMD3100. Proliferation was not affected by SDF-1αor its analogs. Surface antigen detection of CXCR4 was reduced upon treatment with SDF-1αor AMD3100 and it was enhanced by CTCE-9908. Despite the fact that all these molecules target the same CXCR4 receptor, CXCR4 agonists and antagonists have selective effects on different functions of the natural molecule.
Postmenopausal Tuberculosis Endometritis
Authors: Güngördük Kemal , Ulker Volkan , Sahbaz Ahmet , Ark Cemal , Tekırdag Alı Ismet
Published: May 2007

Tuberculosis remains a global health problem, primarily in developing countries with inadequate health services. A significant portion of tuberculosis in these settings is extrapulmonary, including tuberculosis of the genitourinary tract. Patients with genital tuberculosis are usually young women detected during work up for infertility. After menopause, tuberculosis of the endometrium is a rare possibility probably because of the decreased vascularity of the tissues. We present a case of endometrial tuberculosis with postmenopausal vaginal bleeding.
Effect of Silver Addition on the Ethanol-Sensing Properties of Indium Oxide Nanoparticle Layers: Optical Absorption Study
Authors: Singh Vidya Nand , Mehta Bodh Raj , Joshi Rakesh Kumar , Kruis Frank Einar
Published: May 2007

In2O3andIn2O3:Ag nanoparticle layers have been deposited using a two-step method consisting of chemical capping and dip coating techniques. The result of optical absorption analysis ofIn2O3:Ag samples shows the presence ofAg2Oand Ag in air-annealed and vacuum-annealed samples, respectively. These results have been correlated with the gas sensing properties of these layers towards ethanol and support the proposed mechanism that increase in sensor response on Ag addition is due to the conversion ofAg2Oto Ag in the presence of ethanol.
Investigations on the Blade Vibration of a Radial Inflow Micro Gas Turbine Wheel
Authors: Guo Shijie
Published: May 2007

This paper demonstrates the investigations on the blade vibration of a radial inflow micro gas turbine wheel. Firstly, the dependence of Young's modulus on temperature was measured since it is a major concern in structure analysis. It is demonstrated that Young's modulus depends on temperature greatly and the dependence should be considered in vibration analysis, but the temperature gradient from the leading edge to the trailing edge of a blade can be ignored by applying the mean temperature. Secondly, turbine blades suffer many excitations during operation, such as pressure fluctuations (unsteady aerodynamic forces), torque fluctuations, and so forth. Meanwhile, they have many kinds of vibration modes, typical ones being blade-hub (disk) coupled modes and blade-shaft (torsional, longitudinal) coupled modes. Model experiments and FEM analysis were conducted to study the coupled vibrations and to identify the modes which are more likely to be excited. The results show that torque fluctuations and uniform pressure fluctuations are more likely to excite resonance of blade-shaft (torsional, longitudinal) coupled modes. Impact excitations and propagating pressure fluctuations are more likely to excite blade-hub (disk) coupled modes.
Global Existence and Blow-Up Solutions and Blow-Up Estimates for Some Evolution Systems withp-Laplacian with Nonlocal Sources
Authors: Cui Zhoujin , Yang Zuodong
Published: May 2007

This paper deals withp-Laplacian systemsut−div(|∇u|p−2∇u)=∫Ωvα(x,t)dx,x∈Ω,t>0,vt−div(|∇v|q−2∇v)=∫Ωuβ(x,t)dx,x∈Ω, t>0,with null Dirichlet boundary conditions in a smooth bounded domainΩ⊂ℝN, wherep,q≥2,α,β≥1. We first get the nonexistence result for related elliptic systems of nonincreasing positive solutions. Secondly by using this nonexistence result, blow up estimates for abovep-Laplacian systems with the homogeneous Dirichlet boundary value conditions are obtained underΩ=BR={x∈ℝN:|x|0). Then under appropriate hypotheses, we establish local theory of the solutions and obtain that the solutions either exist globally or blow up in finite time.
Strong Convergence of Modified Implicit Iteration Processes for Common Fixed Points of Nonexpansive Mappings
Authors: Zhang Fang , Su Yongfu
Published: May 2007

Strong convergence theorems are obtained by hybrid method for modified composite implicit iteration process of nonexpansive mappings in Hilbert spaces. The results presented in this paper generalize and improve the corresponding results of Nakajo and Takahashi (2003) and others.
Modelling of the Separation Process in a FerrohydrostaticSeparator Using Discrete Element Method
Authors: Murariu V. , Sergeant P. J.
Published: May 2007

This paper presents a model of the separation process in a ferrohydrostatic separator (FHS) which has been designed and developed at DBGS, De Beers, South Africa. The model was developed using special discrete element method software package called Particle Flow Code in 3D (PFC3D). Special attention has been paid to the selection of the simulation parameters in order to achieve the required feed rates. The simulation was carried out using spherical particles and density tracers of different sizes
and densities ranging between 0.004 and 0.008 m and 2700 and 3800 kg/m3, respectively. The tracers were used to set the apparent density of the ferrofluid (the cut‐point) and to provide a measurement of the efficiency of the separation. The model is replacing the ferrofluid by imposing a drag force on the particle. The results of the simulation were presented in the form of the distribution of the density tracers into the sink fraction. These results are realistic and show the advantages of DEM to understand the complex flow behavior of granular materials.
Homomorphisms and Derivations inC*-Algebras
Authors: Park Choonkil , Najati Abbas
Published: May 2007

Using the Hyers-Ulam-Rassias stability method of functional equations, we investigate homomorphisms inC*-algebras, LieC*-algebras, andJC*-algebras, and derivations onC*-algebras, LieC*-algebras, andJC*-algebras associated with the following Apollonius-type additive functional equationf(z−x)+f(z−y)+(1/2)f(x+y)=2f(z−(x+y)/4).
Inductorless Chua's Circuit: Experimental Time Series Analysis
Authors: Rubinger R. M. , Nascimento A. W. M. , Mello L. F. , Rubinger C. P. L. , Filho N. Manzanares , Albuquerque H. A.
Published: May 2007

We have implemented an operational amplifier inductorless realization of the Chua's circuit. We have registered time series from its dynamical variables with the resistorRas the control parameter and varying from 1300Ωto 2000Ω. Experimental time series at fixedRwere used to reconstruct attractors by the delay vector technique. The flow attractors and their Poincaré maps considering parameters such as the Lyapunov spectrum, its subproduct the Kaplan-Yorke dimension, and the information dimension are also analyzed here. The results for a typical double scroll attractor indicate a chaotic behavior characterized by a positive Lyapunov exponent and with a Kaplan-Yorke dimension of 2.14. The occurrence of chaos was also investigated through numerical simulations of the Chua's circuit set of differential equations.
Catalyst Composition and Content Effects on the Synthesis of Single-Walled Carbon Nanotubes by Arc Discharge
Authors: Zhao Tingkai , Tang Qinghu , Liu Yongning , Zhu Changchun , Zhao Xiang
Published: May 2007

Single-walled carbon nanotubes (SWCNTs) were prepared by a modified arc discharging furnace using Fe-Ni-Mg powders as catalyst at600∘C. The effects of catalyst composition and content on the production rate and purity of SWCNTs are investigated in this paper. When the Fe-Ni-Mg catalyst composition is 2: 1: 2wt%and the catalyst content is 5wt%, the experimental results indicate that the production of SWCNTs is 12 grams per hour, and the purity and diameter of SWCNTs are70%and 1.22∼1.38 nm, respectively. The results indicate that the cooperative function of catalyst composition and content plays an important role in the production of SWCNTs. The aim of this work is to control the production process of SWCNTs efficiently.
Normalisation of Multicondition cDNA Macroarray Data
Authors: Dawes Nicola L. , Glassey Jarka
Published: May 2007

Background. Normalisation is a critical step in obtaining meaningful information from the high-dimensional DNA array data. This is particularly important when complex biological hypotheses/questions, such a functional analysis and regulatory interactions within biological systems, are investigated. A nonparametric, intensity-dependent normalisation method based on global identification of self-consistent set (SCS) of genes is proposed here for such systems.Results. The SCS normalisation is introduced and its behaviour demonstrated for a range of user-defined parameters affecting sits performance. It is compared to a standard global normalisation method in terms of noise reduction and signal retention.Conclusions. The SCS normalisation results using 16 macroarray data sets from aBacillus subtilisexperiment confirm that the method is capable of reducing undesirable experimental variation whilst retaining important biological information. The ease and speed of implementation mean that this method can be easily adapted to other multicondition time/strain series single colour array data.
Adipose-Derived Stem Cells for Regenerative Medicine
Authors: Gimble Jeffrey M. , Katz Adam J. , Bunnell Bruce A.
Published: May 2007

The emerging field of regenerative medicine will require a reliable source of stem cells in addition to biomaterial scaffolds and cytokine growth factors. Adipose tissue represents an abundant and accessible source of adult stem cells with the ability to differentiate along multiple lineage pathways. The isolation, characterization, and preclinical and clinical application of adipose-derived stem cells (ASCs) are reviewed in this article.
Stroboscopic Stutter: on the not-yet-captured ontological condition of limit-attractions
Authors: Caspão Paula
Published: May 2007

This second installment of TDR's continuing series on choreography and philosophy addresses dance and temporality. Paula Caspão describes the economy of movement and language as a stuttering, relational, affective field. Frédéric Pouillaude argues that contemporaneity links dance and scène, which in French means both an abstract place for an event and, more concretely, the stage. In a dialogue, Danielle Goldman and Deborah Hay follow up on Goldman's considerations of how improvisation offers “escape routes”—for and from dance, theory, and time.
Gut Feeling: Thomas Hirschhorn'sSuperficial Engagement
Authors: Westcott James
Published: May 2007

What is the relationship of an artwork to the sociopolitical context in which that work was created? James Westcott discusses how Thomas Hirschhorn in Superficial Engagement reproduces the violence of war propaganda. Magda Romanska analyzes the trial in Poland of Dorota Nieznalska, accused of “offending religious feelings” with her work Passion. Ilka Saal reports on the 15th International Istanbul Theater Festival where emerging artists break with both the state and aging Western notions of the avantgarde.
On the Stages of Istanbul: Atatürk and the New Young Turks
Authors: Saal Ilka
Published: May 2007

What is the relationship of an artwork to the sociopolitical context in which that work was created? James Westcott discusses how Thomas Hirschhorn in Superficial Engagement reproduces the violence of war propaganda. Magda Romanska analyzes the trial in Poland of Dorota Nieznalska, accused of “offending religious feelings” with her work Passion. Ilka Saal reports on the 15th International Istanbul Theater Festival where emerging artists break with both the state and aging Western notions of the avantgarde.
Intercultural Expectations: I La Galigo in Singapore
Authors: Lindsay Jennifer
Published: May 2007

When Robert Wilson's I La Galigo premiered in Singapore in 2005, intercultural expectations ran high. The commentary in Singapore and Indonesia after the event assessed the performance in terms of its meeting these expectations. But these judgments, often stated in cultural or nationalistic terms, blinded commentators to other forms of exchange pertinent to I La Galigo.
Improved Subfilter-Scale Models from the HATS Field Data
Authors: Hatlee Stephen C. , Wyngaard John C.
Published: May 2007

An earlier paper proposed simple rate-equation models for subfilter-scale (SFS) scalar flux and deviatoric stress in the terra incognita—that is, in numerical modeling applications where the filter (grid-mesh) scale is of the order of the scale of the turbulence. Here the physics in these models is extended and further tested against data from the Horizontal Array Turbulence Study (HATS) experiment. It is found that extensions of the SFS scalar-flux model do not appreciably improve its performance, although an advection term (which could easily be used in modeling applications) substantially and realistically increases the fluctuation level of SFS scalar flux. The addition of buoyancy and rapid-mean-shear terms to the SFS stress model does improve its performance, bringing it to the level of the scalar-flux model.
Mesoscale Spectra of Mars’s Atmosphere Derived from MGS TES Infrared Radiances
Authors: Imamura Takeshi , Kawasaki Yasuhiro , Fukuhara Tetsuya
Published: May 2007

Wavenumber spectra of the atmospheric potential energy of Mars at mesoscales (wavelengths of 64–957 km) were obtained as a function of latitude, season, and Martian year using infrared radiance data obtained by the Thermal Emission Spectrometer (TES) onboard the Mars Global Surveyor (MGS) spacecraft. Spectral slopes tend to be flatter at smaller scales, and the slopes are usually flatter than −1 near small-scale ends. Near large-scale ends, the spectra sometimes show prominent steepening with slopes from −2 to −3. The power peaks in the high latitudes in winter and equinoxes, suggesting that eddies are generated preferentially in baroclinic zones. The seasonal variation at each latitude band, on the other hand, tends to be obscured by large interannual variability. An enhancement in the power was observed around the storm tracks in the Southern Hemisphere. Spectra of the terrestrial stratosphere were also obtained with a similar method from data taken by the Aura satellite and compared to the results for Mars.
Review article: Three new complementing second language acquisition textbooks
Authors: Foley Claire
Published: May 2007

Three new textbooks in second language acquisition (SLA) differ in their aims. Saville-Troike (2006) offers a concise introductory text with an interdisciplinary approach. De Bot, Lowie and Verspoor (2005) provide a more comprehensive and more advanced introductory text with excerpts from the scholarly literature. Sanz (2005) presents an edited volume representing research in various subfields within an information-processing approach to SLA. All three offer valuable material for instructors to draw on, and they complement one another in interesting ways.
La télévision de l'intimité
Authors: Mehl Dominique
Published: May 2007

Cet article analyse le rapport complexe entre la `télévision de l'intimité' (`talk shows', `reality shows', `real télé') et l'évolution dans les perceptions des domaines `privé' et `public' en France. Quelles nouvelles for-mules et pratiques télévisuelles ont émergé depuis le début des années quatre-vingt-dix? Quels aspects de la vie quotidienne et personnelle sont ainsi mis en scène? Qu'impliquent ces émissions pour les participants et comment influent-elles sur le spectateur? Un climat dans lequel citoyens ordinaires aussi bien que membres de l'establishment s'exposent volontiers au regard finit par effacer les frontières entre le privé et le public, donnant libre cours aux définitions subjectives. L'article conclut que l'espace privé/public du témoignage ne signe ni la mort de l'espace public ni l'aphonie de l'espace privé mais une articulation particulière où le pluralisme des témoignages se présente comme le garant virtuel de l'énoncé de points de vue différents et donc de la potentialité même d'un débat.
The Public and the Private in Contemporary French Politics
Authors: Kuhn Raymond
Published: May 2007

This article examines selected aspects of the changing public/private interface in the mediatisation of politicians in contemporary France. It argues that there is normative confusion surrounding attempts to establish an agreed dividing line between the public and the private in both politicians' mediated communication and journalists' political coverage. Such confusion is a product of mutually reinforcing changes in the interdependent relationship between three sets of actors: politicians, journalists and the public. Politicians need to use the media for the purposes of self-publicity and the projection of a coherent electoral image; journalists operate in highly competitive media markets which are dominated by the pursuit of audiences and advertising revenue; and the public as voters have become disenchanted with the political class, while as media users they have become accustomed to the exposure of the private lives of celebrities.
Reconfiguring the Public and the Private
Authors: Jordan Shirley
Published: May 2007

This article analyses the public and the private in the work of Christine Angot with a particular focus on her 2006 text Rendez-vous and an emphasis on her articulation of intimacy, exposure and vulnerability. Angot is first contextualised through broad analysis of the trend in France for radically self-revelatory cultural production by women, which reconfigures the public/private divide and brings us to consider it in postfeminist perspective. Whereas the disruption of public/private categories remains clearly implicated in feminist narratives of empowerment in the case of writers such as Annie Ernaux and Catherine Millet, Angot appears to destabilise such narratives by repeatedly rehearsing, as well as engendering, vulnerability. The article argues that vulnerability stems from the central textual problematic of incest in Angot, and posits a double reading of incest: incest as testimony and incest as trope. In conclusion, it is suggested that Angot's potently insistent exposure of the incest taboo is not merely an example of, but an overarching metaphor for, the contemporary culture of exposure in `reality' genres.
The Public and the Private in the Lives of Jean-Paul Sartre
Authors: Drake David
Published: May 2007

This article examines some of the complexities of biographical writing with specific reference to five biographies of Jean-Paul Sartre: a memoir (Simone de Beauvoir), a biography (Annie Cohen-Solal), a récit (Liliane Siegel), a psychological biography (Jean-Pierre Boulé) and a third-party account of the Sartre—Beauvoir relationship (Hazel Rowley). These different texts have been selected because each illustrates a particular aspect of the relationship between the public and the private both with specific regard to the life of Sartre and more generally in the genre of biography. These biographies differ from each other not just because of the discovery of new primary material over time, but because the authors examine their subject from radically different perspectives.
Myeloma bone disease and proteasome inhibition therapies
Authors: Terpos Evangelos , Sezer Orhan , Croucher Peter , Dimopoulos Meletios-Athanassios
Published: May 2007

Bone disease is one of the most debilitating manifestations of multiple myeloma. A complex interdependence exists between myeloma bone disease and tumor growth, creating a vicious circle of extensive bone destruction and myeloma progression. Proteasome inhibitors have recently been shown to promote bone formation in vitro and in vivo. Preclinical studies have demonstrated that proteasome inhibitors, including bortezomib, which is the first-in-class such agent, stimulate osteoblast differentiation while inhibiting osteoclast formation and bone resorption. Clinical studies are confirming these observations. Bortezomib counteracts the abnormal balance of osteoclast regulators (receptor activator of nuclear factor-κB ligand and osteoprotegerin), leading to osteoclast inhibition and decreased bone destruction, as measured by a reduction in markers of bone resorption. In addition, bortezomib stimulates osteoblast function, possibly through the reduction of dickkopf-1, leading to increased bone formation, as indicated by the elevation in bone-specific alkaline phosphatase and osteocalcin. The effect of bortezomib on bone disease is thought to be direct and not only a consequence of the agent's antimyeloma properties, making it an attractive agent for further investigation, as it may combine potent antimyeloma activity with beneficial effects on bone. However, the clinical implication of these effects requires prospective studies with specific clinical end points.
MN1 overexpression induces acute myeloid leukemia in mice and predicts ATRA resistance in patients with AML
Authors: Heuser Michael , Argiropoulos Bob , Kuchenbauer Florian , Yung Eric , Piper Jessica , Fung Stephen , Schlenk Richard F. , Dohner Konstanze , Hinrichsen Tanja , Rudolph Cornelia , Schambach Axel , Baum Christopher , Schlegelberger Brigitte , Dohner Hartmut , Ganser Arnold , Humphries R. Keith
Published: May 2007

Overexpression of wild-type MN1 is a negative prognostic factor in patients with acute myeloid leukemia (AML) with normal cytogenetics. We evaluated whether MN1 plays a functional role in leukemogenesis. We demonstrate using retroviral gene transfer and bone marrow (BM) transplantation that MN1 overexpression rapidly induces lethal AML in mice. Insertional mutagenesis and chromosomal instability were ruled out as secondary aberrations. MN1 increased resistance to all-trans retinoic acid (ATRA)–induced cell-cycle arrest and differentiation by more than 3000-fold in vitro. The differentiation block could be released by fusion of a transcriptional activator (VP16) to MN1 without affecting the ability to immortalize BM cells, suggesting that MN1 blocks differentiation by transcriptional repression. We then evaluated whether MN1 expression levels in patients with AML (excluding M3-AML) correlated with resistance to ATRA treatment in elderly patients uniformly treated within treatment protocol AMLHD98-B. Strikingly, patients with low MN1 expression who received ATRA had a significantly prolonged event-free (P = .008) and overall (P = .04) survival compared with patients with either low MN1 expression and no ATRA, or high MN1 expression with or without ATRA. MN1 is a unique oncogene in hematopoiesis that both promotes proliferation/self-renewal and blocks differentiation, and may become useful as a predictive marker in AML treatment.
Stringent and reproducible tetracycline-regulated transgene expression by site-specific insertion at chromosomal loci with pre-characterised induction characteristics
Authors: Brough Rachel , Papanastasiou Antigoni M , Porter Andrew CG
Published: May 2007

Background

The ability to regulate transgene expression has many applications, mostly concerning the analysis of gene function. Desirable induction characteristics, such as low un-induced expression, high induced expression and limited cellular heterogeneity, can be seriously impaired by chromosomal position effects at the site of transgene integration. Many clones may therefore need to be screened before one with optimal induction characteristics is identified. Furthermore, such screens must be repeated for each new transgene investigated, and comparisons between clones with different transgenes is complicated by their different integration sites.

Results

To circumvent these problems we have developed a "screen and insert" strategy in which clones carrying a transgene for a fluorescent reporter are first screened for those with optimal induction characteristics. Site-specific recombination (SSR) is then be used repeatedly to insert any new transgene at the reporter transgene locus of such clones so that optimal induction characteristics are conferred upon it. Here we have tested in a human fibrosarcoma cell line (HT1080) two of many possible implementations of this approach. Clones (e.g. Rht14-10) in which a GFP reporter gene is very stringently regulated by the tetracycline (tet) transactivator (tTA) protein were first identified flow-cytometrically. Transgenes encoding luciferase, I-Sce I endonuclease or Rad52 were then inserted by SSR at a LoxP site adjacent to the GFP gene resulting stringent tet-regulated transgene expression. In clone Rht14-10, increases in expression from essentially background levels (+tet) to more than 104-fold above background (-tet) were reproducibly detected after Cre-mediated insertion of either the luciferase or the I-Sce I transgenes.

Conclusion

Although previous methods have made use of SSR to integrate transgenes at defined sites, none has effectively combined this with a pre-selection step to identify integration sites that support optimal regulatory characteristics. Rht14-10 and similar HT1080-derived clones can now be used in conjunction with a convenient delivery vector (pIN2-neoMCS), in a simple 3-step protocol leading to stringent and reproducible transgene regulation. This approach will be particularly useful for transgenes whose products are very active at low concentrations and/or for comparisons of multiple related transgenes.
Development of expression vectors for Escherichia coli based on the pCR2 replicon
Authors: Walia Rupali , Deb J K , Mukherjee K J
Published: May 2007

Background

Recent developments in metabolic engineering and the need for expanded compatibility required for co-expression studies, underscore the importance of developing new plasmid vectors with properties such as stability and compatibility.

Results

We utilized the pCR2 replicon of Corynebacterium renale, which harbours multiple plasmids, for constructing a range of expression vectors. Different antibiotic-resistance markers were introduced and the vectors were found to be 100% stable over a large number of generations in the absence of selection pressure. Compatibility of this plasmid was studied with different Escherichia coli plasmid replicons viz. pMB1 and p15A. It was observed that pCR2 was able to coexist with these E.coli plasmids for 60 generations in the absence of selection pressure. Soluble intracellular production was checked by expressing GFP under the lac promoter in an expression plasmid pCR2GFP. Also high level production of human IFNγ was obtained by cloning the h-IFNγ under a T7 promoter in the expression plasmid pCR2-IFNγ and using a dual plasmid heat shock system for expression. Repeated sub-culturing in the absence of selection pressure for six days did not lead to any fall in the production levels post induction, for both GFP and h-IFNγ, demonstrating that pCR2 is a useful plasmid in terms of stability and compatibility.

Conclusion

We have constructed a series of expression vectors based on the pCR2 replicon and demonstrated its high stability and sustained expression capacity, in the absence of selection pressure which will make it an efficient tool for metabolic engineering and co-expression studies, as well as for scale up of expression.
Dissociation Kinetics and Complexation Equilibrium Studies of a ZnII Complex with 1,5-Bis(2-hydroxy-5-sulfophenyl)-3-cyanoformazan during Capillary Electrophoretic Separation Process
Authors: Takahashi Toru , Takehara Yuka , Hoshino Hitoshi
Published: May 2007

The dissociation kinetics and the complexation equilibrium of a ZnII complex with 1,5-bis(2-hydroxy-5-sulfophenyl)-3-cyanoformazan (hscf: H5L) during capillary electrophoretic (CE) separation process were studied. The solvolytic dissociation reaction rate constants of the ZnII–hscf complex ([ZnL]3−) (kd) in the pH range of 6.4 to 8.0 were determined with a CE-based dissociation kinetic analysis method. Small kd values on the order of 10−5 s−1 showed the remarkable kinetic inertness of [ZnL]3−, which was detectable in the CE system. The stability constant of [ZnL]3− (KZnL) at 293 K and I = 0.10 was estimated to be [ZnL3−]/{[Zn2+][L5−]} = 1024.2±0.3 through the spectrophotometric titration. The thermodynamic stability of [ZnL]3− in the pre-capillary complexation stage was thus demonstrated. In contrast, it was shown that the CE separation environment is thermodynamically unsuitable for the metal complexes based on the conditional stability constant of [ZnL]3−, which was determined under CE separation conditions, and the concentration of free HSCF in the complex band in the capillary. Thus, the “stability” of metal complex in the CE system strongly depends on kinetic inertness rather than thermodynamic stability, though their thermodynamic stability is necessary for the pre-capillary derivatization step.
Synthesis, Structures, and Properties of Nickel(II) Mixed-Ligand Complexes Containing Various β-Diketonates and a Phosphorus Donor Bidentate Ligand
Authors: Arakawa Machiko , Miyamae Hiroshi , Fukuda Yutaka
Published: May 2007

New mixed-ligand nickel(II) complexes containing β-diketonates and 1,2-bis(diphenylphosphino)ethane, [Ni(dike)(dppe)]X (X = BF4, ClO4, and NO3) were synthesized and characterized. Since the ligand field strength of the phosphorus donor is very strong, the complexes [Ni(dike)(dppe)]X studied in this work are as stable as the square-planar both in solid state and in solutions.
Do social and cognitive deficits curtail musical understanding? Evidence from autism and Down syndrome
Authors: Heaton Pamela , Allen Rory , Williams Kerry , Cummins Omar , Happé Francesca
Published: May 2007

Children with autism experience difficulties in understanding social affective cues, and it has been suggested that such deficits will generalize to music. In order to investigate this proposal, typically developing individuals and children with autism and Down syndrome were compared on tasks measuring perception of affective and movement states in music. The results showed that discrimination performance on both experimental conditions depended on chronological or verbal mental age rather than diagnosis. The findings suggest that emotion‐processing deficits in the social domain do not generalize to music, and that musical understanding is closely related to the level of language development.
Comparison of Brain Natriuretic Peptide (BNP) and Amino-Terminal ProBNP for Early Diagnosis of Heart Failure
Authors: Emdin Michele , Passino Claudio , Prontera Concetta , Fontana Marianna , Poletti Roberta , Gabutti Alessandra , Mammini Chiara , Giannoni Alberto , Zyw Luc , Zucchelli Giancarlo , Clerico Aldo
Published: May 2007

Background: We compared the diagnostic accuracy of brain natriuretic peptide (BNP) and amino-terminal proBNP (NT-proBNP) for diagnosis of preclinical and mild heart failure (HF).

Methods: We assayed plasma NT-proBNP and BNP in 182 healthy controls and in a prospective cohort of 820 HF patients divided according to the American Heart Association/American College of Cardiology classification. These included 86 patients in stage A [mean (SE) ejection fraction 61% (1%); mean (SE) age 47 (2) years], 255 in stage B [65% (2%); 62 (1) years], 420 patients in stage C [35% (1%); 68 (1) years] and 59 in stage D [25% (1%); 74 (1) years]. Diagnostic accuracies of BNP and NT-proBNP were evaluated by ROC analysis, and a multivariate linear regression model was applied to predict HF staging.

Results: Median BNP and NT-proBNP concentrations increased from stage A to D 57-fold and 107-fold, respectively. Both assays were accurate (P <0.001) in separating stage B from controls or stage A, and stage C from controls or stage A or B. NT-proBNP was more accurate (P <0.001) than BNP in differentiating stage C from stages A and B patients and controls and was a better predictor of HF classification in a model including age, sex, and renal function (P <0.001).

Conclusions: Monitoring BNP or NT-proBNP enabled identification of asymptomatic patients at risk for the development of HF. NT-proBNP showed better accuracy than BNP for identifying mild HF.