bluuebunny/crossref_metadata_2025 huggingface dataset:
Soil deformation and its spectral signature
Authors: Wells Robert R. , Prasad S. N. , Römkens M. J. M.
Published: October 2006

Spatial variation of the surface micro‐relief in a Sharkey clay soil was investigated. The micro‐relief measurements of the soil surface were obtained using an automated infrared laser system and evaluated with methods of Fourier analysis. The authors illustrate the spectral technique with a simple example and then use the technique to interpret the surface micro‐relief patterns of soil samples subjected to three simulated rainstorm intensities. The periodicity of the soil surface micro‐relief in the longitudinal direction was 80–120 mm. The periodic surface micro‐relief patterns immediately following the rainstorm are shown to be an early manifestation of the cracking pattern. Published in 2006 by John Wiley & Sons, Ltd.
Study of the erosion rates in the upper Maracujá Basin (Quadrilátero Ferrífero/MG, Brazil) by the in situ produced cosmogenic 10Be method
Authors: Salgado André , Varajão César , Colin Fabrice , Braucher Régis , Varajão Angélica , Nalini Jr Herminio
Published: October 2006

The present work quantifies the erosive processes in the two main substrates (schists–phyllites and granites–gneisses) of the upper Maracujá Basin in the Quadrilátero Ferrífero/MG, Brazil, a region of semi‐humid tropical climate. Two measuring methods of concentration were used: (i) in situ produced 10Be in quartz veins (surface erosion rates) and (ii) 10Be in fluvial sediments (basin erosion rates). The results confirm that (i) erosion tends to be more aggressive close to the headwaters than in the lower parts of the basin and (ii) the region is now affected by dissection. Copyright © 2006 John Wiley & Sons, Ltd.
Enhancement of osteoblast gene expression by mechanically compatible porous Si‐rich nanocomposite
Authors: Gupta Gautam , El‐Ghannam Ahmed , Kirakodu Sreenatha , Khraisheh Marwan , Zbib Hussein
Published: October 2006

Synthesis of a porous bioactive ceramic implant for load bearing applications is a challenging task in maxillofacial and orthopedic surgeries. A novel bioactive resorbable silica‐calcium phosphate nanocomposite (SCPC) has recently been introduced as a potential bone graft. In the present study, we employed SCPC to develop a resorbable porous scaffold and analyzed the effects of composition and porosity on the mechanical properties. The ranges of compressive strength and modulus of elasticity of SCPC containing 32–56% porosity were 1.5–50 MPa and 0.14–2.1 GPa, respectively, which matched the corresponding values for trabecular bone. The compressive strength of dense SCPC was dependent on the Si content and acquired values (93–285 MPa) comparable to that of cortical bone. The superior mechanical properties of SCPC are attributed to the intricate interactions at the boundaries of the nanograins and to the homogenous distribution of hierarchical pore‐structure throughout the material volume. X‐ray computed tomography and mercury porosimetry analyses revealed high interconnectivity of the pores in the size range 3 nm to 650 μm. Quantitative real‐time PCR analyses showed that neonatal rat calvarial osteoblasts attached to Si‐rich SCPC expressed 5‐ and 26‐fold higher osteocalcin mRNA levels compared to cells attached to ProOsteon™ hydroxyapatite disks and tissue culture polystyrene plates respectively, after four days in culture. Results of the present study strongly suggest that porous, bioactive resorbable SCPCs can serve as tissue engineering scaffolds for cell delivery to treat load‐bearing bone defects in orthopedic and maxillofacial surgeries. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Accurate relativistic adapted Gaussian basis sets for Cesium through Radon without variational prolapse and to be used with both uniform sphere and Gaussian nucleus models
Authors: Haiduke Roberto L. A. , Da Silva Albérico B. F.
Published: October 2006

Accurate relativistic adapted Gaussian basis sets (RAGBSs) from Cs (Z = 55) through Rn (Z = 86) without variational prolapse were developed by using the polynomial version of the Generator Coordinate Dirac‐Fock method. The RAGBSs presented here can be used with any of two popular finite nucleus models, the uniform sphere and the Gaussian models. The largest RAGBS error is 4.5 mHartree for Radon with a size of 30s27p17d11f. © 2006 Wiley Periodicals, Inc. J Comput Chem, 2006
The use of time series modeling for the determination of rainfall climates of Iran
Authors: Soltani S. , Modarres R. , Eslamian S. S.
Published: October 2006

In this study, regional climates of Iran were identified based on the properties of the monthly rainfall time series models of 28 main cities of Iran. The autocorrelation (ACF) and partial autocorrelation (PACF) of selected series revealed the seasonal behavior of the monthly rainfall. After the parameters of the models were estimated and the residuals of the models analysed to be time independent and the normality was checked using Portmanteau lack of fit and nonparametric tests, the multiplicative ARIMA model was fitted to monthly rainfall time series of the stations. To determine regional climates, a hierarchical cluster analysis was applied on autocorrelation coefficients at different lags and three main climatic groups were found based on the time series models, namely, simple, moderate and complex climates. The results of the time series modeling showed a high variation of the temporal pattern of the monthly rainfall over Iran except for the margins of the Caspian Sea and the Persian Gulf. The study also shows that the correlation between the seasonal autocorrelation coefficient of the rainfall time series and the rainfall coefficient of variation and elevation of the stations is significant while lag‐one autocorrelation coefficient does not correlate to rainfall coefficient of variation and the elevation of the stations. Different models also imply the high variation in the spatial rainfall producing mechanism and different stationarity and periodicity characteristics of the rainfall temporal pattern over Iran. A nomenclature of the abbreviation is given at the end of the paper. Copyright © 2006 Royal Meteorological Society
Optimization via experimental design of an SPE‐HPLC‐UV‐fluorescence method for the determination of valsartan and its metabolite in human plasma samples
Authors: Iriarte Gorka , Ferreirós Nerea , Ibarrondo Izaskun , Alonso Rosa Maria , Maguregi Miren Itxaso , Gonzalez Lorena , Jiménez Rosa Maria
Published: October 2006

A chemometric approach was applied for the optimization of the extraction and separation of the antihypertensive drug valsartan and its metabolite valeryl‐4‐hydroxy‐valsartan from human plasma samples. Due to the high number of experimental and response variables to be studied, fractional factorial design (FFD) and central composite design (CCD) were used to optimize the HPLC‐UV‐fluorescence method. First, the significant variables were chosen with the help of FFD; then, a CCD was run to obtain the optimal values for the significant variables. The measured responses were the corrected areas of the two analytes and the resolution between the chromatographic peaks. Separation of valsartan, its metabolite valeryl‐4‐hydroxy‐valsartan and candesartan M1, used as internal standard, was made using an Atlantis dC18 100 mm×3.9 mm id, 100 Å, 3 μm chromatographic column. The mobile phase was run in gradient elution mode and consisted of ACN with 0.025% TFA and a 5 mM phosphate buffer with 0.025% TFA at pH 2.5. The initial percentage of ACN was 32% with a stepness of 4.5%/min to reach the 50%. A flow rate of 1.30 mL/min was applied throughout the chromatographic run, and the column temperature was kept to 40 ± 0.2°C. In the SPE procedure, experimental design was also used in order at achieve a maximum recovery percentage and extracts free from plasma interferences. The extraction procedure for spiked human plasma samples was carried out using C8 cartridges, phosphate buffer (pH 2, 60 mM) as conditioning agent, a washing step with methanol‐phosphate buffer (40 : 60 v/v), a drying step of 8 min, and diethyl ether as eluent. The SPE‐HPLC‐UV‐fluorescence method developed allowed the separation and quantitation of valsartan and its metabolite from human plasma samples with an adequate resolution and a total analysis time of 1 h.
Comprehensive two‐dimensional gas chromatographic analysis of commercial lemon‐flavored beverages
Authors: Komura Hajime
Published: October 2006

Fresh lemon juice and lemon‐flavored beverages were analyzed by using comprehensive 2‐D GC (GC×GC) with flame‐ionization detection, with a nonpolar–polar column combination. A low‐alcohol, ready‐to‐drink (RTD) beverage was also analyzed as fresh, and after deterioration for 12 days at 50°C. Identification of some of the components in the 2‐D plots was performed by comparison of peak positions of authentic standards and comparison with 1‐D GC. However, without the aid of GC×GC‐mass spectral data, only 24 components were identified; a large number of components remained unassigned. In some soft drinks obtained in the market, components indicative of deterioration, such as p‐methylacetophenone and p‐cymen‐8‐ol were already present in the products. In contrast, even upon heat challenge, a low‐alcohol RTD beverage did not generate deterioration products of citral, such as p‐methylacetophenone and the intermediates, p‐menth‐2‐ene‐1,8‐diols. This was apparently related to the fact that the original formulation contained only a minute amount of the citral ingredient.
Effect of quetiapine in psychotic Parkinson's disease patients: A double‐blind labeled study of 3 months' duration
Authors: Rabey Jose M. , Prokhorov Tatiana , Miniovitz Ala , Dobronevsky Eugenia , Klein Colin
Published: October 2006

This double‐blind randomized study examined the effect of quetiapine (QTP) on drug‐induced psychosis (DIP) in Parkinson's disease (PD). Conventional antipsychotic drugs are associated with adverse extrapyramidal effects. QTP is a new atypical antipsychotic drug used in the treatment of psychosis in PD. A total of 58 consecutive psychotic PD patients (mean age, 75 ± 8.3 years; mean disease duration, 10.5 ± 6.4 years; 29 with dementia) were randomly assigned to 2 groups: 30 were treated with QTP (mean dose, 119.2 ± 56.4 mg) and 28 received placebo for 3 months. The motor part of the Unified Parkinson's Disease Rating Scale, the Brief Psychiatric Rating Scale, the Mini‐Mental State Examination, the Hamilton Rating Scale for Depression, the Epworth Sleepiness Score, and the Clinical Global Impression Scale were administered before and during the study. No significant difference was found between the groups in all parameters. There were 32 PD patients (55%) completed the 3‐month study (15 [26%] QTP and 17 [29%] placebo). Treatment was interrupted in 15 patients in the QTP and 11 in the placebo groups. This double‐blind study did not show a beneficial effect of QTP for the treatment of DIP in PD. The high rate of withdrawal probably influenced the results. Larger double‐blind studies are required. © 2006 Movement Disorder Society
On the Lp–Lq maximal regularity for Stokes equations with Robin boundary condition in a bounded domain
Authors: Shimada Rieko
Published: October 2006

We obtain the Lp–Lq maximal regularity of the Stokes equations with Robin boundary condition in a bounded domain in ℝn (n⩾2). The Robin condition consists of two conditions: v ⋅ u=0 and αu+β(T(u, p)v – 〈T(u, p)v, v〉v)=h on the boundary of the domain with α, β⩾0 and α+β=1, where u and p denote a velocity vector and a pressure, T(u, p) the stress tensor for the Stokes flow and v the unit outer normal to the boundary of the domain. It presents the slip condition when β=1 and non‐slip one when α=1, respectively. The slip condition is appropriate for problems that involve free boundaries. Copyright © 2006 John Wiley & Sons, Ltd.
Needle electromyography of the rectus abdominis in patients with amyotrophic lateral sclerosis
Authors: Xu Yingsheng , Zheng Juyang , Zhang Shuo , Kang Dexuan , Zhang Jun , Fan Dongsheng
Published: October 2006

We examined the role of needle electromyography (EMG) of the rectus abdominis (RA) in assessing thoracic involvement in amyotrophic lateral sclerosis (ALS). Needle EMG of the RA was performed in 67 patients with sporadic ALS and 110 healthy controls. The presence of abnormal spontaneous activity, configuration of motor unit action potentials (MUAPs), and recruitment pattern of motor unit potentials were examined. In ALS patients, MUAPs in the RA were of prolonged duration, large amplitude, and showed increased prevalence of polyphasic waveforms compared to controls. Significant differences in MUAP parameters, presence of abnormal spontaneous potentials, and interference patterns were noted between ALS patients and controls. Additionally, we found that active denervation was more frequent in the RA of ALS patients with dyspnea than those without dyspnea. Thus, conventional needle EMG of the RA is a valuable electrophysiological method to assess clinical and subclinical involvement of thoracic lower motor neurons in patients with suspected ALS. Muscle Nerve, 2006
Thermodynamic effects of proline introduction on protein stability
Authors: Prajapati Ravindra Singh , Das Mili , Sreeramulu Sridhar , Sirajuddin Minhajuddin , Srinivasan Sankaranarayanan , Krishnamurthy Vaishnavi , Ranjani Ranganathan , Ramakrishnan C. , Varadarajan Raghavan
Published: October 2006

The amino acid Pro is more rigid than other naturally occurring amino acids and, in proteins, lacks an amide hydrogen. To understand the structural and thermodynamic effects of Pro substitutions, it was introduced at 13 different positions in four different proteins, leucine–isoleucine–valine binding protein, maltose binding protein, ribose binding protein, and thioredoxin. Three of the maltose binding protein mutants were characterized by X‐ray crystallography to confirm that no structural changes had occurred upon mutation. In the remaining cases, fluorescence and CD spectroscopy were used to show the absence of structural change. Stabilities of wild type and mutant proteins were characterized by chemical denaturation at neutral pH and by differential scanning calorimetry as a function of pH. The mutants did not show enhanced stability with respect to chemical denaturation at room temperature. However, 6 of the 13 single mutants showed a small but significant increase in the free energy of thermal unfolding in the range of 0.3–2.4 kcal/mol, 2 mutants showed no change, and 5 were destabilized. In five of the six cases, the stabilization was because of reduced entropy of unfolding. However, the magnitude of the reduction in entropy of unfolding was typically several fold larger than the theoretical estimate of −4 cal K−1 mol−1 derived from the relative areas in the Ramachandran map accessible to Pro and Ala residues, respectively. Two double mutants were constructed. In both cases, the effects of the single mutations on the free energy of thermal unfolding were nonadditive. Proteins 2007. © 2006 Wiley‐Liss, Inc.
Core Electron Binding Energy (CEBE) as Descriptors in Quantitative Structure–Activity Relationship (QSAR) Analysis of Cytotoxicities of a Series of Simple Phenols
Authors: Takahata Yuji , Arakawa Masmoto , Funatsu Kimito , Costa Maria Cristina Andreazza , Segala Maximiliano
Published: October 2006

Core Electron Binding Energies (CEBEs) of ring carbon atoms in 4‐X‐phenols were calculated using density‐functional theory with the scheme ΔEKS (PW86‐PW91)/TZP//HF/6‐31G*. The phenols show toxicity to fast growing cells. Using CEBEs of four distinguished carbon atoms in the phenyl ring and oxygen atom in OH of the phenols, the compounds were well separated and grouped by Principal Component Analysis (PCA). Using three out of the five CEBEs, together with σ+ and log P of the phenols as descriptor, we established a QSAR model with Partial Least Squares (PLS) regression which resulted in Q2=0.914. CEBE values when used together with traditionally used descriptors such as log P and σ+ turned out to be useful descriptors in modeling the activity (QSAR) of the compounds with PLS.
Feedback control synthesis of multiple frequency domain specifications via generalized KYP lemma
Authors: Iwasaki T. , Hara S.
Published: October 2006

This paper considers a control synthesis problem for linear systems to meet design specifications in terms of multiple frequency domain inequalities in (semi)finite ranges. Our approach is based on the generalized Kalman–Yakubovich–Popov (GKYP) lemma, and dynamic output feedback controllers of order equal to the plant are considered. A new multiplier expansion is proposed to convert the synthesis condition to a linear matrix inequality (LMI) condition through a standard linearizing change of variables. In a single objective setting, the LMI condition may or may not be conservative, depending on the choice of the basis for the multiplier expansion. We provide a qualification for the basis matrix to yield non‐conservative LMI conditions. It is difficult to determine the basis matrix meeting such a qualification in general. However, it is shown that qualified bases can be found for some cases, and that the qualification condition can be used to find reasonable choices of the basis for other cases. The synthesis method is then extended to the multiple objective case where a sufficient condition is given for the existence of a controller to meet all the prescribed specifications. Finally, design examples for an active magnetic bearing are given to illustrate the effectiveness of the proposed design method. Copyright © 2006 John Wiley & Sons, Ltd.
Tutorial in biostatistics: competing risks and multi‐state models
Authors: Putter H. , Fiocco M. , Geskus R. B.
Published: October 2006

Standard survival data measure the time span from some time origin until the occurrence of one type of event. If several types of events occur, a model describing progression to each of these competing risks is needed. Multi‐state models generalize competing risks models by also describing transitions to intermediate events. Methods to analyze such models have been developed over the last two decades. Fortunately, most of the analyzes can be performed within the standard statistical packages, but may require some extra effort with respect to data preparation and programming. This tutorial aims to review statistical methods for the analysis of competing risks and multi‐state models. Although some conceptual issues are covered, the emphasis is on practical issues like data preparation, estimation of the effect of covariates, and estimation of cumulative incidence functions and state and transition probabilities. Examples of analysis with standard software are shown. Copyright © 2006 John Wiley & Sons, Ltd.
Tables for the analysis of selective predation experiments
Authors: Manly B. F. J.
Published: October 2006

This paper discusses the analysis of selective predation experiments with two types of prey when the prey are not replaced after they have been removed by the predators. In an earlier paper (Manlyet al., 1972) consideration was given to situations where the replication of experiments allows the estimation of standard errors from the experimental results; in the present paper a table of standard errors is given for a large range of experiments and replication is therefore no longer necessary. The standard errors were calculated on an electronic computer by solving the exact equations given in the earlier paper.

The suggested method of analysis is illustrated using some data where the prey were red and yellow artificial ‘maggots’ and the predators were garden birds.
The ingestion in wolf spiders II. The expression of degree of hunger and amount of ingestion in relation to spider's hunger
Authors: Nakamura Kazuo
Published: October 2006

To express the degree of hunger during both of feeding and unfeeding periods of spiders, equations for the amount of ingestion and food disappearance from the gut were presented using three components: capacity of gut, rate of ingestion and rate of food disappearance. The degree of hunger was expressed by the rate of unfilled capacity of gut to the capacity of gut based on these equations.

The rates of ingestion and food disappearance were estimated from the results of experiment with a wolf spider, Pardosa laura. The equations obtained well applied to the experimental result. By changing values of these rates, it was revealed that the ratio of rates of ingestion to food disappearance determine the amount of ingestion.
Resolving the limitation – regulation debate
Authors: White T. C. R.
Published: October 2006

Many recent ecological studies have demonstrated that animal populations are limited by their food. Examples are presented here to refute the view that natural populations are regulated by negative feedback mortality factors. Additionally, several incorrect statements in a recent publication are discussed, specifically (1) that there is no difference between the concepts of regulation and limitation; (2) that the debate is about what causes the time it takes a population to reach the carrying capacity of its habitat, not what sets that carrying capacity; (3) that the results of a laboratory experiment using a closed population with fixed amounts of food represents what happens in natural open populations with varying supplies of food; (4) that a thermostat analogy can be used, assuming that an “equilibrium” is controlling natural populations “from above” instead of the original steam analogy which says the varying input of a resource “from below” is the controlling factor.
Acoustic study of the Río de la Plata estuarine front
Authors: Cabreira A.G. , Madirolas A. , Alvarez Colombo G. , Acha E.M. , Mianzan H.W.
Published: October 2006

During December 1999, a transect 260 km long was carried out along the major axis of the Río de la Plata estuary. Acoustic (120 kHz), oceanographic, and zooplankton sampling were performed to extract a continuous, quasi-synoptic acoustic view of the estuary's salt wedge. Three different zones were identified. The riverine and marine zones were characterized by vertically homogeneous water and low volume-backscattering strength (Sv). The mixohaline zone was characterized by a strong vertical salinity gradient and the highest Sv values. There were no relationships between the reflection value calculated from the salinity gradient and suspended matter (sediments) and measured Sv. The greatest abundance of acoustically detectable organisms was at the halocline depth, coincident with the echo recordings. The positions of the halocline and the two fronts were determined on the basis of aggregations of the different planktonic groups. The physical presence of the salt wedge, as shown by a “biological wedge”, was well described by the acoustic technique employed.
The REBENT monitoring network, a spatially integrated, acoustic approach to surveying nearshore macrobenthic habitats: application to the Bay of Concarneau (South Brittany, France)
Authors: Ehrhold Axel , Hamon Dominique , Guillaumont Brigitte
Published: October 2006

A 200-km2 area in the Bay of Concarneau on the South Brittany coast was surveyed acoustically using different sidescan sonars (a 100-kHz EdgeTech DF1000, and a 240-kHz Reson SeaBat 8101). The area corresponds to a sector of the REBENT network. It was selected for its physical and biological characteristics, reflecting the sedimentary heterogeneity and biological diversity of Brittany's coastal seafloors. The work presented here illustrates the methodology for mapping subtidal seabed habitats in the context of the network. Backscatter mosaics were produced covering 100% of the survey area. Extensive ground-truthing was carried out involving 93 Shipek grab samples and 25 drop-down video profiles. From interpretation of the acoustic facies, 40 biological soft-bottom stations were sampled using a Hamon grab to characterize macrobenthic communities (>2 mm). The results indicated considerable variation in backscatter responses in relation to high densities of macrobenthic species (Lithothamnion, Asterias, Haploops, Maldane, Ophiocomina), and a wide variety of substratum types present within a relatively small area. Dense biocenoses of maerl were accurately surveyed from 20-m to <5-m depth (Lower Astronomical Tide; LAT). Boundaries of Haploops communities are associated with dense small pockmarks in the centre of the bay. The relationships between sediment sometimes colonized by macrobenthic species and backscatter responses are discussed.
Spatio-temporal patterns in maturation of the chokka squid (Loligo vulgaris reynaudii) off the coast of South Africa
Authors: Olyott L.J.H. , Sauer W.H.H. , Booth A.J.
Published: October 2006

Knowledge of the temporal and spatial characteristics of chokka squid (Loligo vulgaris reynaudii) biology in South African waters is limited, so the possibility of there being a geographically fragmented stock was examined by investigating the distribution of maturity patterns for the species, covering all known spawning areas and using both historical and recent data. Gonadosomatic indices (GSI) varied between year-round consistency and apparent seasonal peaks in both summer and winter; there was no clear spatial pattern. Monthly percentage maturity provided further evidence for two peak reproductive periods each year, although mature squid were present throughout. Sex ratios demonstrated great variability between different areas and life history stages. Male-biased sex ratios were only apparent on the inshore spawning grounds and ranged between 1.118:1 and 4.267:1. Size at sexual maturity was also seasonal, squid maturing smaller in winter/spring than in summer/autumn. Also, squid in the east matured smaller than squid in the west. Although the results from the present study do not provide conclusive evidence of distinct geographic populations, squid likely spawn over a significantly larger area of the Agulhas Bank than previously estimated, and squid on the west coast of South Africa may return to spawn on the western portion of the Agulhas Bank. It remains likely, however, that the east and west coast populations are a single stock and that migration of juveniles to the west coast and their subsequent return as sub-adults is an integral but non-essential and variable part of the life history.
Thyroid hormone deficiency changes the distribution of oligodendrocyte/myelin markers during oligodendroglial differentiation in vitro
Authors: Younes‐Rapozo V. , Berendonk J. , Savignon T. , Manhães A.C. , Barradas P.C.
Published: October 2006

Myelination depends on the proper differentiation of oligodendrocytes and several factors may influence this event. For instance, thyroid hormone (T3) affects the timing of differentiation and regulates the expression of several enzymes involved in the synthesis of complex lipids and in the expression of some myelin structural proteins. We investigated the effect of T3 deficiency on oligodendroglial differentiation and in the distribution of oligodendrocyte/myelin proteins 2′3′‐cyclic nucleotide 3′‐phosphodiesterase (CNPase) and myelin basic protein (MBP). Oligodendroglial‐enriched cultures were obtained from cerebra of neonate rats grown in a modified medium. The T3‐deficient status was induced by using medium devoid of T3. We observed a delay, in T3‐deficient cultures, in oligodendroglial maturation characterized by less extensive processes and membrane vellum than in controls. In control cultures, CNPase immunoreactivity was punctated, showing cell bodies and processes at earlier stages and redistribution to cytoskeleton vein‐like structures in later stages. In T3‐deficient cultures, CNPase remained in a punctated pattern and only at 10 days in vitro we observed CNPase redistribution to the presumptive cytoskeleton vein‐like structures. MBP in control cultures was distributed through the whole cell body and processes whereas in T3‐deficient cultures, MBP immunoreactivity was concentrated in the perinuclear region. These results reinforce the hypothesis that T3 is an important factor in oligodendrocyte differentiation, particularly regarding the distribution of myelin proteins.
International institutions are the key: a new perspective on the democratic peace
Authors: HASENCLEVER ANDREAS , WEIFFEN BRIGITTE
Published: October 2006

The international organisation of the democratic peace matters. Interdemocratic institutions are particularly suited to block escalation pathways between states and to prevent conflicts from resulting in war. This article builds on findings from three fields of research: (a) the liberal analysis of the democratic peace; (b) systemic approaches to international institutions, and (c) new quantitative studies of armed conflicts. Three pivotal contributions of international institutions to peaceful conflict management are identified: international institutions can be used to overcome the security dilemma among states and to tame power competitions. They sustain international cooperation and forestall the recourse of governments to unilateral self-help strategies. Finally, international institutions increase the autonomy of issue areas, which decreases the risk of destabilising spillover effects from other issue areas. The article holds that these three functions are extraordinarily well performed by international institutions composed of democracies and illustrates this allegation by presenting three case studies of interdemocratic management of former rivalries. Therefore, the distinctive features of interdemocratic institutions merit more attention as a supplement to the explanation of the democratic peace.
Determining the temporally and radially resolved temperature distribution inside a pulsed broad-area vertical-cavity surface-emitting laser cavity
Authors: Mandre Shyam K. , Elsäßer Wolfgang , Fischer Ingo , Peeters Michael , Verschaffelt Guy
Published: October 2006

The authors experimentally determine temporally and radially resolved profiles of the temperature distribution within the cavity of a broad-area vertical-cavity surface-emitting laser in pulsed operation. For this, the recently discovered state of spatially incoherent emission [M. Peeters et al., Opt. Express 13, 9337 (2005)] is harnessed. Using single-shot measurements of spectrally resolved near field profiles acquired by a fast-gated charge coupled device camera, the wavelength shift due to heating of the device is temporally and radially resolved. From the wavelength shift the temperature shift is extracted, which finally allows for determination of absolute temperature profiles.
Chlamydial TARP is a bacterial nucleator of actin
Authors: Jewett Travis J. , Fischer Elizabeth R. , Mead David J. , Hackstadt Ted
Published: October 2006

Chlamydia trachomatis
entry into host cells results from a parasite-directed remodeling of the actin cytoskeleton. A type III secreted effector, TARP (translocated actin recruiting phosphoprotein), has been implicated in the recruitment of actin to the site of internalization. To elucidate the role of TARP in actin recruitment, we identified host cell proteins that associated with recombinant GST-TARP fusions. TARP directly associated with actin, and this interaction promoted actin nucleation as determined by
in vitro
polymerization assays. Domain analysis of TARP identified an actin-binding domain that bears structural and primary amino acid sequence similarity to WH2 domain family proteins. In addition, a proline-rich domain was found to promote TARP oligomerization and was required for TARP-dependent nucleation of new actin filaments. Our findings reveal a mechanism by which chlamydiae induce localized cytoskeletal changes by the translocated effector TARP during entry into host cells.
Inhomogeneous dynamics in confined water nanodroplets
Authors: Dokter Adriaan M. , Woutersen Sander , Bakker Huib J.
Published: October 2006

The effect of confinement on the dynamical properties of liquid water was studied by mid-infrared ultrafast pump–probe spectroscopy on HDO:D
2
O in reverse micelles. By preparing water-containing reverse micelles of different well defined sizes, we varied the degree of geometric confinement in water nanodroplets with radii ranging from 0.2 to 4.5 nm. We find that water molecules located near the interface confining the droplet exhibit slower vibrational energy relaxation and have a different spectral absorption than those located in the droplet core. As a result, we can measure the orientational dynamics of these different types of water with high selectivity. We observe that the water molecules in the core show similar orientational dynamics as bulk water and that the water layer solvating the interface is highly immobile.
A seven-helix coiled coil
Authors: Liu Jie , Zheng Qi , Deng Yiqun , Cheng Chao-Sheng , Kallenbach Neville R. , Lu Min
Published: October 2006

Coiled-coil proteins contain a characteristic seven-residue sequence repeat whose positions are designated a to g. The interacting surface between α-helices in a classical coiled coil is formed by interspersing nonpolar side chains at the a and d positions with hydrophilic residues at the flanking e and g positions. To explore how the chemical nature of these core amino acids dictates the overall coiled-coil architecture, we replaced all eight e and g residues in the GCN4 leucine zipper with nonpolar alanine side chains. Surprisingly, the alanine-containing mutant forms a stable α-helical heptamer in aqueous solution. The 1.25-Å resolution crystal structure of the heptamer reveals a parallel seven-stranded coiled coil enclosing a large tubular channel with an unusual heptad register shift between adjacent staggered helices. The overall geometry comprises two interleaved hydrophobic helical screws of interacting cross-sectional a and d layers that have not been seen before. Moreover, asparagines at the a positions play an essential role in heptamer formation by participating in a set of buried interhelix hydrogen bonds. These results demonstrate that heptad repeats containing four hydrophobic positions can direct assembly of complex, higher-order coiled-coil structures with rich diversity for close packing of α-helices.
miR-7b, a microRNA up-regulated in the hypothalamus after chronic hyperosmolar stimulation, inhibits Fos translation
Authors: Lee Heon-Jin , Palkovits Miklós , Young W. Scott
Published: October 2006

The transcription factor activator protein 1 (AP-1) is formed through the dimerization of immediate–early genes Fos and Jun family members. Activator protein 1 is known as a pivotal regulator of major biological events such as cell proliferation, differentiation, organogenesis, memory formation, and apoptosis. During a search for microRNAs (miRNAs; small, endogenous, noncoding RNAs that repress gene expression of target mRNAs in animals posttranscriptionally) that are differentially expressed in the mouse paraventricular and supraoptic nuclei after 10 days of drinking 2% saline, one candidate microRNA that is relatively highly expressed, mmu-miR-7b (miR-7b), was studied further because sequence analysis suggested a likely interaction with the 3′ untranslated region of
Fos
mRNA. We show that miR-7b expression inhibits Fos translation
in vitro
and that it and its host gene are prominently expressed in the PVN and other brain areas, including the suprachiasmatic nucleus. No effect on
Fos
mRNA levels was observed. Normally, Fos is expressed at low to undetectable levels in cells, but it shows rapid induction and decay after acute stimuli. Various pathways have been identified through which Fos family proteins are degraded; our results indicate a significant additional mechanism by which Fos protein and activity may be regulated.
Suppression of hypoxia-induced HIF-1α and of angiogenesis in endothelial cells by
myo
-inositol trispyrophosphate-treated erythrocytes
Authors: Kieda Claudine , Greferath Ruth , Crola Da Silva Claire , Fylaktakidou Konstantina C. , Lehn Jean-Marie , Nicolau Claude
Published: October 2006

Allosteric regulation of oxygen delivery by RBCs may have significant effects on tumor growth. Indeed, angiogenesis, the formation of new blood vessels, is induced in growing tumors by low oxygen partial pressure. Hypoxia-inducible genes are switched on, among which are the VEGF gene and its receptors. Most important, under hypoxia, hypoxia-inducible factor 1α has a significantly prolonged half-life and up-regulates a number of hypoxia genes. Human microvascular endothelial cells (MECs), when subjected
in vitro
to hypoxia, align to form vessel-like structures as in the angiogenic process. We report here that, when cultured in hypoxic conditions in the presence of human RBCs loaded with a new membrane-permeant allosteric effector of Hb,
myo
-inositol trispyrophosphate (ITPP), endothelial cells (ECs) do not align, i.e., do not form “vessel”-like structures, because the “loaded” RBCs are capable of releasing under hypoxia more oxygen than their “normal” counterparts. Levels of VEGF and of hypoxia-inducible factor 1α, elevated in the human MECs under hypoxia, were dramatically reduced or even suppressed in the presence of the ITPP-loaded RBCs. Treatment of these ECs directly with free ITPP at different concentrations had no effect on their ability to undertake angiogenesis. Incubation with ITPP enhances the capacity of Hb to release bound oxygen, leading to higher oxygen tension in the hypoxic environment, thus inhibiting hypoxia-induced angiogenesis. These observations are suggestive of a potential
in vivo
role of ITPP-loaded, “low-O
2
-affinity” RBCs in cancer therapy.
Comparative genomics of the lactic acid bacteria
Authors: Makarova K. , Slesarev A. , Wolf Y. , Sorokin A. , Mirkin B. , Koonin E. , Pavlov A. , Pavlova N. , Karamychev V. , Polouchine N. , Shakhova V. , Grigoriev I. , Lou Y. , Rohksar D. , Lucas S. , Huang K. , Goodstein D. M. , Hawkins T. , Plengvidhya V. , Welker D. , Hughes J. , Goh Y. , Benson A. , Baldwin K. , Lee J.-H. , Díaz-Muñiz I. , Dosti B. , Smeianov V. , Wechter W. , Barabote R. , Lorca G. , Altermann E. , Barrangou R. , Ganesan B. , Xie Y. , Rawsthorne H. , Tamir D. , Parker C. , Breidt F. , Broadbent J. , Hutkins R. , O'Sullivan D. , Steele J. , Unlu G. , Saier M. , Klaenhammer T. , Richardson P. , Kozyavkin S. , Weimer B. , Mills D.
Published: October 2006

Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.
Critical role for the β regulatory subunits of Cav channels in T lymphocyte function
Authors: Badou Abdallah , Jha Mithilesh Kumar , Matza Didi , Mehal Wajahat Z. , Freichel Marc , Flockerzi Veit , Flavell Richard A.
Published: October 2006

Calcium ion is a universal signaling intermediate, which is known to control various biological processes. In excitable cells, voltage-gated calcium channels (Cav) are the major route of calcium entry and regulate multiple functions such as contraction, neurotransmitter release, and gene transcription. Here we show that T lymphocytes, which are nonexcitable cells, express both regulatory β and pore-forming Cav1 α1 subunits of Cav channels, and we provide genetic evidence for a critical role of the Cav β3 and Cav β4 regulatory subunits in T lymphocyte function. Cav β-deficient T lymphocytes fail to acquire normal functions, and they display impairment in the T cell receptor-mediated calcium response, nuclear factor of activated T cells activation, and cytokine production. In addition, unlike in excitable cells, our data suggest a minimal physiological role for depolarization in Cav channel opening in T cells. T cell receptor stimulation induces only a small depolarization of T cells, and artificial depolarization of T cells using KCl does not lead to calcium entry. These observations suggest that the Cav channels expressed by T cells have adopted novel regulation/gating mechanisms.
Resolution of a chronic viral infection after interleukin-10 receptor blockade
Authors: Ejrnaes Mette , Filippi Christophe M. , Martinic Marianne M. , Ling Eleanor M. , Togher Lisa M. , Crotty Shane , von Herrath Matthias G.
Published: October 2006

A defining characteristic of persistent viral infections is the loss and functional inactivation of antiviral effector T cells, which prevents viral clearance. Interleukin-10 (IL-10) suppresses cellular immune responses by modulating the function of T cells and antigen-presenting cells. In this paper, we report that IL-10 production is drastically increased in mice persistently infected with lymphocytic choriomeningitis virus. In vivo blockade of the IL-10 receptor (IL-10R) with a neutralizing antibody resulted in rapid resolution of the persistent infection. IL-10 secretion was diminished and interferon γ production by antiviral CD8+ T cells was enhanced. In persistently infected mice, CD8α+ dendritic cell (DC) numbers declined early after infection, whereas CD8α− DC numbers were not affected. CD8α− DCs supported IL-10 production and subsequent dampening of antiviral T cell responses. Therapeutic IL-10R blockade broke the cycle of IL-10–mediated immune suppression, preventing IL-10 priming by CD8α− DCs and enhancing antiviral responses and thereby resolving infection without causing immunopathology.
Large-Scale cis-Element Detection by Analysis of Correlated Expression and Sequence Conservation between Arabidopsis and Brassica oleracea
Authors: Haberer Georg , Mader Michael T. , Kosarev Peter , Spannagl Manuel , Yang Li , Mayer Klaus F.X.
Published: October 2006

The rapidly increasing amount of plant genomic sequences allows for the detection of cis-elements through comparative methods. In addition, large-scale gene expression data for Arabidopsis (Arabidopsis thaliana) have recently become available. Coexpression and evolutionarily conserved sequences are criteria widely used to identify shared cis-regulatory elements. In our study, we employ an integrated approach to combine two sources of information, coexpression and sequence conservation. Best-candidate orthologous promoter sequences were identified by a bidirectional best blast hit strategy in genome survey sequences from Brassica oleracea. The analysis of 779 microarrays from 81 different experiments provided detailed expression information for Arabidopsis genes coexpressed in multiple tissues and under various conditions and developmental stages. We discovered candidate transcription factor binding sites in 64% of the Arabidopsis genes analyzed. Among them, we detected experimentally verified binding sites and showed strong enrichment of shared cis-elements within functionally related genes. This study demonstrates the value of partially shotgun sequenced genomes and their combinatorial use with functional genomics data to address complex questions in comparative genomics.
Modifications to the Arabidopsis Defense Proteome Occur Prior to Significant Transcriptional Change in Response to Inoculation withPseudomonas syringae
Authors: Jones Alexandra M.E. , Thomas Vincent , Bennett Mark H. , Mansfield John , Grant Murray
Published: October 2006

Alterations in the proteome of Arabidopsis (Arabidopsis thaliana) leaves during responses to challenge by Pseudomonas syringae pv tomato DC3000 were analyzed using two-dimensional gel electrophoresis. Protein changes characteristic of the establishment of disease, basal resistance, and resistance-gene-mediated resistance were examined by comparing responses to DC3000, a hrp mutant, and DC3000 expressing avrRpm1, respectively. The abundance of each protein identified was compared with that of selected transcripts obtained from comparable GeneChip experiments. We report changes in three subcellular fractions: total soluble protein, chloroplast enriched, and mitochondria enriched over four time points (1.5–6 h after inoculation). In total, 73 differential spots representing 52 unique proteins were successfully identified. Many of the changes in protein spot density occurred before significant transcriptional reprogramming was evident between treatments. The high proportion of proteins represented by more than one spot indicated that many of the changes to the proteome can be attributed to posttranscriptional modifications. Proteins found to show significant change after bacterial challenge are representative of two main functional groups: defense-related antioxidants and metabolic enzymes. Significant changes to photosystem II and to components of the mitochondrial permeability transition were also identified. Rapid communication between organelles and regulation of primary metabolism through redox-mediated signaling are supported by our data.
Mutants of Arabidopsis Lacking Starch Branching Enzyme II Substitute Plastidial Starch Synthesis by Cytoplasmic Maltose Accumulation
Authors: Dumez Sylvain , Wattebled Fabrice , Dauvillee David , Delvalle David , Planchot Véronique , Ball Steven G. , D'Hulst Christophe
Published: October 2006

Three genes, BE1, BE2, and BE3, which potentially encode isoforms of starch branching enzymes, have been found in the genome of Arabidopsis thaliana. Although no impact on starch structure was observed in null be1 mutants, modifications in amylopectin structure analogous to those of other branching enzyme II mutants were detected in be2 and be3. No impact on starch content was found in any of the single mutant lines. Moreover, three double mutant combinations were produced (be1 be2, be1 be3, and be2 be3), and the impact of the mutations on starch content and structure was analyzed. Our results suggest that BE1 has no apparent function for the synthesis of starch in the leaves, as both be1 be2 and be1 be3 double mutants display the same phenotype as be2 and be3 separately. However, starch synthesis was abolished in be2 be3, while high levels of α-maltose were assayed in the cytosol. This result indicates that the functions of both BE2 and BE3, which belong to class II starch branching enzymes, are largely redundant in Arabidopsis. Moreover, we demonstrate that maltose accumulation depends on the presence of an active ADP-glucose pyrophosphorylase and that the cytosolic transglucosidase DISPROPORTIONATING ENZYME2, required for maltose metabolization, is specific for β-maltose.