bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimization of scan parameters in pulmonary partial pressure oxygen measurement by hyperpolarized 3He MRI
Authors: Yu Jiangsheng , Ishii Masaru , Law Michelle , Woodburn John M. , Emami Kiarash , Kadlecek Stephen , Vahdat Vahid , Guyer Richard A. , Rizi Rahim R.
Published: November 2007

The dependence of hyperpolarized (HP) 3He T1 on local oxygen concentration provides the basis for measuring the partial pressure of oxygen (pO2) and oxygen depletion rate (R) in the lungs. Precise measurements of this type are difficult because the oxygen effect manifests itself through a decay of signal, leading to noisy images at the end of the series. The depolarization caused by RF excitation pulses further complicates the problem. It is therefore important to optimize scan parameters, such as measurement timing and flip angle, to obtain accurate and reproducible measurements. This work presents a new single‐acquisition technique in conjunction with the multiple regression fitting method for data evaluation. Analytical expressions for the measurement uncertainties are derived. A total of four types of single‐acquisition timing schemes are investigated; simulation shows a large uncertainty variation between these schemes (pO2: 7.5–30.2%; R: 47.4–173.7%). A basic procedure for optimizing scan parameters is then described. A phantom experiment was conducted to verify the simulation results. Repeated in vivo measurements with the optimal scheme in a rabbit experiment showed that average variation of global mean is 6.2% for pO2 and 12.0% for R, and that the average variation of percentiles (10th, 25th, 50th, 75th, and 90th) is 8.7% for pO2 and 19.0% for R. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.
Quantitative proton spectroscopic imaging of the neurochemical profile in rat brain with microliter resolution at ultra‐short echo times
Authors: Mlynárik Vladimír , Kohler Ingrid , Gambarota Giulio , Vaslin Anne , Clarke Peter G.H. , Gruetter Rolf
Published: November 2007

Proton spectroscopy allows the simultaneous quantification of a high number of metabolite concentrations termed the neurochemical profile. The spin echo full intensity acquired localization (SPECIAL) scheme with an echo time of 2.7 ms was used at 9.4T for excitation of a slab parallel to a home‐built quadrature surface coil in conjunction with phase encoding in the two remaining spatial dimensions to yield an effective spatial resolution of 1.7 μL. The absolute concentrations of at least 10 metabolites were calculated from the spectra of individual voxels using LCModel analysis. The calculated concentrations were used for constructing quantitative metabolic maps of the neurochemical profile in normal and pathological rat brain. Summation of individual spectra was used to assess the neurochemical profile of unique brain regions, such as corpus callosum, in rat for the first time. Following focal ischemia in rat pups, imaging the neurochemical profile indicated increased choline groups in the ischemic core and increased glutamine in the penumbra, which is proposed to reflect glutamate excitotoxicity. We conclude that it is feasible to achieve a sensitivity that is sufficient for quantitative mapping of the neurochemical profile at microliter spatial resolution. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.
19F NMR in vivo spectroscopy reflects the effectiveness of perfusion‐enhancing vascular modifiers for improving gemcitabine chemotherapy
Authors: Cron Greg O. , Beghein Nelson , Ansiaux Réginald , Martinive Philippe , Feron Olivier , Gallez Bernard
Published: November 2007

Nuclear magnetic resonance spectroscopy of fluorine‐19 (19F NMR) has proven useful for evaluating kinetics of fluorinated chemotherapy drugs in tumors in vivo. This work investigated how three perfusion‐enhancing vascular modifiers (BQ123, thalidomide, and Botulinum neurotoxin type A [BoNT‐A]) would affect the chemotherapeutic efficacy of gemcitabine, a fluorinated drug widely used in human cancer treatment. Murine tumor growth experiments demonstrated that only BoNT‐A showed a strong trend to enhance tumor growth inhibition by gemcitabine (1.7 days growth delay, P = 0.052, Student t‐test). In accord with these results, 19F NMR experiments showed that only BoNT‐A increased significantly the uptake of gemcitabine in tumors (50% increase, P = 0.0008, Student t‐test). Further experiments on gemcitabine kinetics (NMR vs time) and distribution (19F MRI) confirmed the uptake‐enhancing properties of BoNT‐A. The results of this study demonstrate that 19F NMR can monitor modulation of the pharmacokinetics of fluorinated chemotherapy drugs in tumors. The results also show that 19F NMR data can give a strong indication of the effectiveness of perfusion‐enhancing vascular modifiers for improving gemcitabine chemotherapy in murine tumors. 19F NMR is a promising tool for preclinical evaluation of such vascular modifiers and may ultimately be used in the clinic to monitor how these modifiers affect chemotherapy. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.
Single‐shot dual‐z‐shimmed sensitivity‐encoded spiral‐in/out imaging for functional MRI with reduced susceptibility artifacts
Authors: Truong Trong‐Kha , Song Allen W.
Published: November 2007

Blood oxygenation level‐dependent (BOLD) functional MRI (fMRI) can be severely hampered by signal loss due to susceptibility‐induced static magnetic field (B0) inhomogeneities near air/tissue interfaces. A single‐shot spiral‐in/out sequence with a z‐shim gradient embedded between the two acquisitions was previously proposed to efficiently recover the signal. However, despite promising results, this technique had several limitations, which are addressed here as follows. First, by adding a second z‐shim gradient before the spiral‐in acquisition and optimizing both z‐shim gradients slice‐by‐slice, a significantly more uniform signal recovery can be achieved. Second, by acquiring a B0 map, the optimal z‐shim gradients can be directly, efficiently, and accurately determined for each subject. Third, by complementing the z‐shimming approach with sensitivity encoding (SENSE), the in‐plane spatial resolution can be increased and, hence, susceptibility artifacts further reduced, while maintaining a high temporal resolution for fMRI applications. These advantages are demonstrated in human functional studies. Magn Reson Med, 2007. © 2007 Wiley‐Liss, Inc.
Think tanks in transitional China
Authors: Zhu Xufeng , Xue Lan
Published: November 2007

There is a growing interest in China's think tanks within and outside China. But many questions remain to be answered. How have their roles changed over time? Why are some think tanks more active than others in some areas, but less so in others? To answer such questions, the authors classify China's think tanks according to organisational structure, as a key explanatory concept. A longitudinal review shows that since the 1970s the organisational structure of think tanks has evolved gradually from semi‐official to civilian, with the evolving structures playing different roles and complementing one another. Following analysis of four case studies of China's think tanks, two of which are semi‐official and two of which are civilian, the article draws a picture of the complex relationship between organisational structure, strategy and behaviour of China's think tanks. Copyright © 2007 John Wiley & Sons, Ltd.
Eyes wide shut? Reforming and defusing checks and balances in Argentina
Authors: Santiso Carlos
Published: November 2007

How effective are autonomous audit agencies (AAAs) in curbing corruption and improving fiscal governance in emerging economies? AAAs are autonomous oversight agencies tasked with scrutinising government finances. However, they are not as effective as they could or should be, partly because of the political constraints they face and the political economy context in which they are embedded. This article assesses the performance and trajectory of the Argentine AAA. It suggests that AAAs can have only a limited impact when formal fiscal institutions are undermined by informal practices and undercut by adverse political incentives. It further highlights the limits of radical reform strategies based on the import of exogenous institutional models. This research has important research and policy implications for the reform and strengthening of AAAs in developing countries. Copyright © 2007 John Wiley & Sons, Ltd.
The contribution of international accounting standards to implementing NPM in developing and developed countries
Authors: Navarro Galera Andrés , Rodríguez Bolívar Manuel Pedro
Published: November 2007

In recent years, numerous countries have undertaken administrative reforms to implement New Public Management (NPM) postulates. The implementation of NPM involves new information needs for decision taking by public managers. In this context, public sector accounting plays a key role as an information system for the successful implementation of NPM. The International Federation of Accountants (IFAC) is undertaking an international accounting harmonisation project to establish high‐quality public sector standards to meet the new information requirements under NPM worldwide. This article examines the capability of IFAC accounting measurement bases to meet information needs under NPM postulates, in both developing and developed countries, analysing the differences between these types of countries. The National Accounting Standard Setters (NASS) of 47 countries were asked about the usefulness and viability of Fair Value Accounting (FVA) to implement NPM postulates, especially those concerning improved efficiency, enhanced information transparency and benchmarking analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Cancer, mental disorders, suicidal ideation and attempts in a large community sample
Authors: Rasic Daniel T. , Belik Shay‐Lee , Bolton James M. , Chochinov Harvey M. , Sareen Jitender
Published: November 2007

Purpose: To determine the association between cancer diagnosis, mental disorders and suicidal behavior among community dwelling adults.

Methods: Data were drawn from the nationally representative Canadian Community Health Survey Cycle 1.2 (N=36 984, response rate 77%, age 15+). Respondents were grouped into three age groups (15–54, 55–74, and 75+ years), and multiple regression analyses were conducted to examine the relationship between cancer and mental disorders: unadjusted and adjusted for sociodemographics, social supports and other mental disorders.

Results: Among respondents aged 15–54, cancer was associated with increased odds of major depression (odds ratio [OR]=3.18; 95% confidence interval [CI]: 1.69–5.96), panic attacks (OR=2.15; 95% CI: 1.22–3.77) and any mental disorder. Among respondents aged 55–75, cancer was associated with increased odds of agoraphobia (OR=5.94; 95% CI: 1.68–21.03) and decreased odds of social phobia (OR=0.22; 95% CI: 0.06–0.80). Cancer was not associated with any mental disorder in the 75+ age group. Results persisted after adjustments for the covariates. Suicidal ideation was associated with cancer in the 55–74 age group (OR=5.07; 95% CI: 1.25–20.47) in unadjusted models; however, this relationship became non‐significant when adjusting for the other covariates.

Conclusion: Clinicians should consider screening for depression and panic disorder in young, community dwelling patients with cancer. Copyright © 2007 John Wiley & Sons, Ltd.
The impact of cancer and quality of life for long‐term survivors
Authors: Zebrack Brad J. , Yi Jaehee , Petersen Laura , Ganz Patricia A.
Published: November 2007

This study reports on health status and quality of life (QOL) outcomes in long‐term cancer survivors, and potential correlates including cancer type, age at diagnosis, health status, and key sociodemographic variables.

Method: One hundred and ninety‐three cancer survivors 5–10 years post‐diagnosis completed a mailed survey assessing physical and mental health status, QOL, post‐traumatic growth, and impact of cancer (IOC).

Results: Respondents were comparable to population norms on physical and mental health status. After controlling for sociodemographic and medical status variables, older respondents reported better overall QOL (p=0.004) and mental health (p<0.001), but worse physical health (p=0.04). Survivors reporting low income (p=0.02) and comorbidities (p=0.003) indicated worse physical functioning. A higher negative IOC score was associated with worse physical functioning (p<0.0001), worse mental health (p<0.0001), and lower overall QOL (p<0.0001). A higher positive IOC score was associated with better mental health (p=0.0004) and better overall QOL (p=0.005).

Conclusion: Perceptions of how cancer has affected survivors' lives in both positive and negative ways may influence, or be influenced by, their functional abilities and QOL. Copyright © 2007 John Wiley & Sons, Ltd.
Mapping the peptide and protein immune response in the larvae of the fleshfly Sarcophaga bullata
Authors: Ciencialová Alice , Neubauerová Tereza , Šanda Miloslav , Šindelka Radek , Cvačka Josef , Voburka Zdeněk , Buděšínský Miloš , Kašička Václav , Sázelová Petra , Šolínová Veronika , Macková Martina , Koutek Bohumír , Jiráček Jiří
Published: November 2007

We chose the larvae of fleshfly Sarcophaga bullata to map the peptide and protein immune response. The hemolymph of the third‐instar larvae of S. bullata was used for isolation. The larvae were injected with bacterial suspension to induce an antimicrobial response. The hemolymph was separated into crude fractions, which were subdivided by RP‐HPLC, gel electrophoresis, and free‐flow electrophoresis. In several fractions, we determined significant antimicrobial activities against the pathogenic bacteria Escherichia coli, Staphylococcus aureus, or Pseudomonas aeruginosa. Among antimicrobially active compounds we identified dipeptide β‐alanyl‐ L‐tyrosine, protein transferrin, and two variants of peptide sapecin. We also partially characterized two novel antimicrobially active polypeptides; odorant‐binding protein 99b, and a peptide which remains unidentified. Copyright © 2007 European Peptide Society and John Wiley & Sons, Ltd.
Bolometric detection of terahertz radiation from new grating gates device
Authors: Meziani Yahya Moubarak , Hanabe Mitsuhiro , Otsuji Taiichi , Sano Eiichi
Published: November 2007

We report on experimental investigations on room temperature emission of the terahertz radiation from a doubly interdigitated grating gate high‐electron mobility transistor. The device was subjected to 1.5‐mm cw beam laser and the detection was performed using a 4.2 K silicon bolometer. The detected signal is interpreted as a self oscillation of the plasma waves. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Initialization and logic gate operations of nuclear spin qubits using a submicron scale resistively‐detected NMR device
Authors: Ota T. , Yusa G. , Kumada N. , Miyashita S. , Fujisawa T. , Hirayama Y.
Published: November 2007

We demonstrate initialization of nuclear spin qubits using a resistively‐detected nuclear magnetic resonance (NMR) device. In our device, nuclear spins are dynamically polarized in a sub‐micron scale region defined by split gates. The population of each nuclear spin state is estimated from a resistively‐detected NMR spectrum combined with numerical analysis. By applying radio frequency pulses to the polarized nuclear spins, we create two‐qubit effective pure states, which is a crucial step toward NMR quantum computation. We also demonstrate simple logic gate operations such as controlled‐NOT and SWAP gates in this two‐qubit system. The obtained spectra are consistent with numerically calculated ones. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ballistic electron mean free path of titanylphthalocyanine films grown on GaAs
Authors: Özcan S. , Smoliner J. , Andrews M. , Strasser G. , Dienel T. , Fritz T.
Published: November 2007

In this article, Au/titanylphthalocyanine/n‐GaAs diodes incorporating ultrathin films of the archetypal organic semiconductor titanylphthalocyanine were investigated by ballistic electron emission microscopy/spectroscopy (BEEM/S). BEEM/S measurements were used to determine the transmission of ballistic electrons through titanylphthalocyanine as a function of energy and temperature. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fourier spectroscopy of decoherence of exciton and their complexes in single InAlAs quantum dots
Authors: Adachi S. , Sasakura H. , Yatsu N. , Kaji R. , Yamada K. , Muto S. , Kumano H. , Suemune I.
Published: November 2007

We report the photon‐correlation Fourier spectroscopy of exciton and exciton complexes in single self‐assembled In0.75Al0.25As/Al0.3Ga0.7As quantum dots. A Michelson interferometer inserted in the photoluminescence path was used to measure the coherent length of the timeaveraged emission of neutral exciton, biexciton, and positive trion. As comparing with their coherence time and their excitation energy dependence, the effects of the exchange interaction and the fluctuation of the surrounding excess charge are discussed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitation power dependence of optically pumped nuclear spin polarizations in single InAlAs QDs
Authors: Kaji R. , Sasakura H. , Adachi S. , Muto S.
Published: November 2007

In a single self‐assembled InAlAs quantum dot, we report the nonlinearity of nuclear spin polarization by optical pumping. Increasing (or decreasing) the excitation power at a particular excitation polarization, nuclear spin polarization shows the abrupt jump (or drop) and a clear hysteresis loop. In addition, the degree of circular polarization of positively charged exciton also exhibits similar bistable behavior and the hysteretic operation has the precise synchronization with the nuclear spin polarization. It suggests that an electron in the positively charged exciton plays a main role to create the abrupt change of the nuclear spin polarization in the observed quantum dot. This abrupt change reveals the sign and magnitude of the electrong‐factors inz‐direction and can be explained by using a simple model calculation. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Inefficiency of intervalley transfer in narrow InGaAs/AlAsSb quantum wells
Authors: Tribuzy C. V.‐B. , Ohser S. , Priegnitz M. , Winnerl S. , Schneider H. , Helm M. , Neuhaus J. , Dekorsy T. , Biermann K. , Künzel H.
Published: November 2007

By using femtosecond pump‐probe spectroscopy we investigate the intersubband relaxation dynamics in narrow InGaAs/AlAsSb quantum wells. A biexponential behavior is an indication of intervalley scattering, which is, however, much slower than known from bulk material. This may be the reason why quantum cascade lasers at wavelengths as short as 3 μm are actually functioning In addition, when pumping slightly below resonance we observe an induced transient absorption, which can be interpreted in terms of electron heating within the first subband. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electron transport in superlattices for interacting Wannier‐Stark levels
Authors: Reggiani Lino , Guida Angelo , Rosini Marcello
Published: November 2007

We develop a microscopic theory of electron transport in superlattices within the Wannier‐Stark approach by including the interaction among the energy levels pertaining to adjacent quantum wells. The main results are: (i) the interaction among the levels is responsible for a systematic increase of the level energy with respect to the bottom of the quantum well at increasing electric fields; (ii) the interaction is responsible for the onset of a new delocalization of the Wannier‐Stark states at the highest fields associated with the tunneling of electrons between adjacent quantum wells; (iii) with respect to the noninteracting case, at the highest fields the average carrier energy evidences a consistent increase which leads to a significant softening of the negative differential value of both the drift velocity and diffusivity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Excitation of millimeter‐wave oscillations in InAlAs/InGaAs heterostructures
Authors: Pérez S. , Mateos J. , Pardo D. , González T.
Published: November 2007

We study the origin of strong Terahertz (THz) oscillations taking place in InAlAs/InGaAs slot diodes ‐ base of High Electron Mobility Transistor (HEMT) devices ‐ when bias surpasses 0.5 V. To this end we perform a microscopic analysis of current fluctuations, calculated by means of an ensemble Monte Carlo (MC) simulator. The millimeter and submillimeter waves are caused by the presence of Gunn‐like oscillations whose dynamics is controlled by ballistic Γ valley electrons in the channel. These carriers are capable to reach extremely high velocities due to the influence of degeneracy effects (preventing scattering mechanisms) and the presence of a recessed geometry. The dependence of this process on the recess and recess‐drain lengths is analyzed in order to improve the frequency and magnitude of the oscillations. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Competition between quantum‐confined Stark effect and free‐carrier screening effect in AlGaN/GaN multiple quantum wells
Authors: Fujita T. , Toizumi T. , Nakazato Y. , Tackeuchi A. , Chinone T. , Liang J. H. , Kajikawa M.
Published: November 2007

The competition between the quantum‐confined Stark effect (QCSE) and the free‐carrier screening effect in AlGaN/GaN multiple quantum wells (MQWs) has been investigated by time‐resolved photoluminescence (PL) measurement. AlGaN/GaN MQWs is a promising material for the next‐generation ultraviolet light‐emitting diodes and laser devices. The large changes in the PL energy and the decay time are observed with changing carrier density. We show that the energy shift and the change in decay time are explained well by the free‐carrier screening effect that compensates for the internal electric field. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Theoretical investigation on the detailed mechanism of the OH‐initiated atmospheric photooxidation of o‐xylene
Authors: Huang Mingqiang , Zhang Weijun , Wang Zhenya , Hao Liqing , Zhao Wenwu , Liu Xianyun , Long Bo , Fang Li
Published: November 2007

The reaction mechanism for o‐xylene with OH radical and O2 was studied by density functional theory (DFT) method. The geometries of the reactants, intermediates, transition states, and products were optimized at B3LYP/6‐31G(d,p) level. The corresponding vibration frequencies were calculated at the same level. The single‐point calculations for all the stationary points were carried out at the B3LYP/6‐311++G(2df,2pd) level using the B3LYP/6‐31G(d,p) optimized geometries. Reaction energies for the formation of the aromatic intermediate radicals have been obtained to determine their relative stability and reversibility, and their activation barriers have been analyzed to assess the energetically favorable pathways to propagate the o‐xylene oxidation. The results of the theoretical study indicate that OH addition to o‐xylene forms ipso, meta, and para isomers of o‐xylene‐OH adducts, and the ipso o‐xylene adduct is the most stable among these isomers. Oxygen is expected to add to the o‐xylene‐OH adducts forming o‐xylene peroxy radicals. And subsequent ring closure of the peroxyl radicals to form bicyclic radicals. With relatively low barriers, isomerization of the o‐xylene bicyclic radicals to more stable epoxide radicals likely occurs, competing with O2 addition to form bicyclic peroxy radicals. The study provides thermochemical data for assessment of the photochemical production potential of ozone and formation of toxic products and secondary organic aerosol from o‐xylene photooxidation. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Applying the concepts of density functional theory to simple systems
Authors: Pearson Ralph G.
Published: November 2007

Equations are derived for the chemical potential and local hardness of the ground states of helium and the related two electron ions. With these properties it is possible to correct the energies of the simple single‐zeta wave functions to the nearly exact values. The calculations are simple for these simple systems. In principle, it is possible to extend this method to all atoms and molecules. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
A computational study of open‐chain epothilone analogue
Authors: Kamel Karol , Rusinska‐Roszak Danuta
Published: November 2007

Molecular mechanics (MM/Ambers) calculations were applied to probe the conformational profile of open‐chain epothilone analogue [Org Lett 2006, 8, 685], cytotoxic against some cell lines. Geometries of the most stable conformers were optimized at DFT level using the B3LYP functional and then compared to known both experimental and virtual conformers of epothilone. One of the most stable structures is III (1.47 kcal/mol above global minimum) which represents high similarity to the appropriate fragment of the Taylor's model of epothilone A, but two other conformers: XIV and XX, although they have almost the same conformation as the mother structure, are very unstable (6.7 and 12.4 kcal/mol above the global minimum). © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
A quantum‐chemical study of phosphor impurity in BaTiO3 crystal
Authors: Stashans Arvids , Vidal Gabriela
Published: November 2007

Structural and electronic effects produced by a P impurity in the cubic and tetragonal BaTiO3 lattices are investigated using a simple quantum chemical computer code based on the Hartree–Fock methodology. The obtained atomic displacements due to the defect present in otherwise pure crystal are mainly toward the impurity atom, thus reducing the interatomic distances within the defective region. It is also found that the phosphor produces some redistribution of electron density from the defect‐neighboring atoms toward the chemical bonds thus diminishing the charges on atoms. We also observe a local energy level in the band‐gap of material being composed mainly of P 3s atomic orbital. The level finds itself close to the top of the upper valence band, in no case contributing into the n‐type conductivity in BaTiO3. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Analysis of transition‐metal acetylacetonate complexes by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry
Authors: Wyatt Mark F. , Havard Stephen , Stein Bridget K. , Brenton A. Gareth
Published: November 2007

Transition‐metal acetylacetonate complexes of the form Metal(acac)2, where Metal = Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), and Metal(acac)3, where Metal = V(III), Cr(III), Mn(III), Fe(III), and Co(III), were investigated by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOFMS). The data was acquired using the aprotic, electron transfer matrix, 2‐[(2E)‐3‐(4‐tert‐butylphenyl)‐2‐methylprop‐2‐enylidene]malononitrile (DCTB), and the observation of positive radical ions is shown clearly to depend on the metal element and the oxidation state it occupies. The ionization energy of DCTB was calculated to be 8.08 eV by density functional theory methods, which is notably lower than the experimental value, but within the range of other computational values. This value is very close to those of the analytes, so the existing electron transfer mechanism which is based on the ionization energies of the matrix and analyte, cannot be used predictively. Similarly, the data neither proves nor disproves the validity of the existing electron transfer ionization mechanism, with respect to metal coordination complexes without strong chromophores. In this case, periodic trends may be more useful in explaining the observed species and the prediction of species from sets of similar complexes. The addition of a sodium salt benefits the MALDI‐TOFMS characterization of certain compounds studied, but the benefit of the addition of ammonium or silver salts is negligible. Copyright © 2007 John Wiley & Sons, Ltd.
The potential role of tributaries as seed sources to an impoundment in Northern Sweden: a field experiment with seed mimics
Authors: Bång Åsa , Nilsson Christer , Holm Svante
Published: November 2007

Fragmentation and flow regulation of rivers by large dams are known to obstruct the longitudinal dispersal of waterborne plant propagules between impoundments, and to affect plant community composition. However, even several decades after a dam has been built, impoundments may still have a relatively species‐rich riparian flora. We hypothesized that free‐flowing tributaries act as the major gene pools for such impoundments, thus alleviating the fragmenting effect large dams have on the main channel. The importance of tributaries as seed sources was tested by releasing wooden seed mimics in three different‐sized (0.22–6.93 m3 s−1) tributaries of an impoundment in the Ume River in Northern Sweden. In each tributary seed mimics were released, during the spring flood peak, from three points approximately 1, 2 and 3 km upstream the outlet in the impoundment. The importance of a tributary as a seed source increased with tributary size. Of the 9000 released seed mimics 1.5% reached the impoundment; 1.2% of the 9000 originated from the largest tributary and 0.3% from the middle‐sized one. The smallest tributary retained all its mimics. Copyright © 2007 John Wiley & Sons, Ltd.
Ignorability and stability assumptions in neighborhood effects research
Authors: VanderWeele Tyler J.
Published: November 2007

Two central assumptions concerning causal inference in the potential outcomes framework for estimating neighborhood effects are examined. The stable unit treatment value assumption in the context of neighborhood effects requires that an individual's outcome does not depend on the treatment assigned to neighborhoods other than the individual's own neighborhood. The assumption is important in that it makes estimation feasible, although some progress can be made even when the assumption is relaxed. Some discussion is given concerning the contexts in which the neighborhood‐level stable unit treatment value assumption is likely to hold. The ignorability assumption allows the researcher to move from conclusions about association to conclusions about causation. In the context of neighborhood‐wide interventions, the ignorability assumption for the individual‐level potential outcomes framework can be easily adapted for neighborhood effects. Copyright © 2007 John Wiley & Sons, Ltd.
IPOG/IPOG‐D: efficient test generation for multi‐way combinatorial testing
Authors: Lei Yu , Kacker Raghu , Kuhn D. Richard , Okun Vadim , Lawrence James
Published: November 2007

This paper presents two strategies for multi‐way testing (i.e.t‐way testing witht>2). The first strategy generalizes an existing strategy, called in‐parameter‐order, from pairwise testing to multi‐way testing. This strategy requires all multi‐way combinations to be explicitly enumerated. When the number of multi‐way combinations is large, however, explicit enumeration can be prohibitive in terms of both the space for storing these combinations and the time needed to enumerate them. To alleviate this problem, the second strategy combines the first strategy with a recursive construction procedure to reduce the number of multi‐way combinations that have to be enumerated. Both strategies are deterministic, i.e. they always produce the same test set for the same system configuration. This paper reports a multi‐way testing tool called FireEye, and provides an analytic and experimental evaluation of the two strategies. Copyright © 2007 John Wiley & Sons, Ltd.
Process intensification of whole‐cell biocatalysis with ionic liquids
Authors: Weuster‐Botz Dirk
Published: November 2007

The unique properties of room temperature ionic liquids such as non‐volatility, nonflammability, and, in many cases, high thermal and chemical stability have made them an environmentally attractive alternative to organic solvents. Biphasic biocatalytic processes with nonmiscible liquid phases are usually applied with whole‐cell biocatalysts to overcome low water solubility of substrates or products, inhibitory effects of the reactants on the biocatalyst, or low stability of substrates or products in the aqueous phase. The surprising noninvasive effects on cellular membranes of hydrophobic ionic liquids especially of those with hexafluorophosphate and bis(trifluoromethylsulfonyl)imide anions in biphasic ionic liquid/water systems make them superior to many organic solvents so far applied in whole‐cell biotransformations. Impressive process intensification in simple biphasic batch processes was recently demonstrated on the examples of asymmetric synthesis with whole‐cell biocatalysts, if the distribution coefficients of inhibitory substrates and products between ionic liquids and aqueous phase exceed a log D of about 2 (e.g., ketones and β‐ketoesters with lipophilic side chains and their corresponding chiral alcohols). © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 7: 334–340; 2007: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20130
Fertility outcomes following expectant management of tubal ectopic pregnancy
Authors: Helmy S. , Sawyer E. , Ofili‐Yebovi D. , Yazbek J. , Nagi J. Ben , Jurkovic D.
Published: November 2007

Objectives

To evaluate fertility outcome after the expectant management of tubal ectopic pregnancy.

Methods

Our dedicated early pregnancy database was searched for all women diagnosed with a tubal ectopic pregnancy between January 1999 and June 2003 who were either managed expectantly or underwent a salpingectomy. They were contacted to enquire about their ability to conceive following the ectopic pregnancy and about the outcomes of any subsequent pregnancies.

Results

Four hundred and forty‐four women had a diagnosis of tubal ectopic pregnancy, and 173 (39%) were successfully contacted. A total of 146/173 (84.4%; 95% CI, 79–89.8%) tried for another pregnancy: 49/59 (83.1%; 95% CI, 73.4–92.6%) in the expectant management and 97/114 (85.1%; 95% CI, 78.4–91.6%) in the salpingectomy group (P > 0.05). Spontaneous intrauterine pregnancy occurred in 41/49 (83.7%; 95% CI, 73.3–94.2%) women managed expectantly and in 62/97 (63.9%; 95% CI, 54.4–73.5%) women managed surgically (odds ratio 2.89; 95% CI, 1.22–6.86%). The risk of recurrent ectopic pregnancy was not significantly different between the two management groups.

Conclusions

Fertility outcomes following the expectant management of tubal ectopic pregnancy are comparable to those following salpingectomy. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
Ophthalmic artery Doppler velocimetry in healthy pregnancy
Authors: Carneiro Raquel S. , Sass Nelson , Diniz Angelica L. , Souza Eder V. , Torloni Maria R. , Moron Antonio F.
Published: November 2007

Objectives

To establish normative data for ophthalmic artery Doppler parameters throughout a healthy pregnancy, to investigate the possible correlation between these Doppler measurements and gestational age, and to test intraobserver variability.

Methods

A prospective cross‐sectional study was performed to assess various Doppler parameters in 276 healthy women between 20 and 39 weeks of gestation. The following measurements were obtained: pulsatility and resistance indices (PI, RI), peak systolic velocity (PSV), peak diastolic velocity (PDV), end diastolic flow velocity (EDFV), and peak ratio (PR). Quantile regression was used to estimate reference values throughout pregnancy and P < 0.05 was considered significant. The intraclass correlation coefficient (Intra‐CC) was used to calculate intraobserver variability.

Results

The 5th and 95th prediction intervals for each gestational age are presented. No significant correlation was detected between Doppler indices and gestational age. Intra‐CC was excellent (0.996).

Conclusions

Reference values were generated for ophthalmic artery Doppler measurements, and they did not vary significantly during healthy pregnancy.
The Shadow of Hierarchy and New Modes of Governance
Authors: HÉRITIER ADRIENNE , LEHMKUHL DIRK
Published: November 2007

This special issue about sectoral governance in the shadow of hierarchy focuses on two sets of questions. Firstly, do new modes of sectoral governance in themselves contribute to the efficacy of policymaking or do they require the shadow of hierarchy, i.e. legislative and executive decisions, in order to deal effectively with the problems they are supposed to solve? And, secondly, what are the institutional links between sectoral governance and territorially bounded democratic governments? How do different links contribute to the efficacy of policymaking and how do they change over time? Is there a retreat of government from policymaking and a corresponding increase of sectoral governance, or just the opposite?
New Modes of Governance in the Shadow of Hierarchy: Self-regulation by Industry in Europe
Authors: HÉRITIER ADRIENNE , ECKERT SANDRA
Published: November 2007

In technically complex areas, political actors increasingly rely on private actors to shape public policy, due to the greater expertise of private actors. This article theorises and empirically investigates the conditions under which self-regulation by industry (governance) emerges in environmental policy at the European level and asks how effective it is. Is a shadow of hierarchy (governmental intervention) needed to ensure the emergence and effectiveness of voluntary agreements? We show that the willingness to engage in self-regulation is prompted by the threat of governmental legislation. Once legislation has been pre-empted, environmental self-regulation is implemented under a weak shadow of hierarchy. We identify the causes of this weak control and explain the differential performance in the two sectors on the basis of different market incentives.
THREE NEW SPECIES OF AGAPETES (ERICACEAE) FROM INDIA
Authors: Banik D. , Sanjappa M.
Published: November 2007

Three new species of Agapetes (Ericaceae) from Arunachal Pradesh, India are described and illustrated with critical comments: Agapetes arunachalensis D.Banik & M.Sanjappa (Agapetes ser. Graciles subser. Parvifoliae), Agapetes dalaiensis D.Banik & M.Sanjappa (Agapetes ser. Agapetes subser. Agapetes) and Agapetes siangensis D.Banik & M.Sanjappa (Agapetes ser. Graciles subser. Longifoliae).
CAN THE SECTIONAL POSITION OF GENTIANA CACHEMIRICA BE CLARIFIED BY A DETAILED ANALYSIS OF ITS MORPHOLOGY?
Authors: Davitashvili N. , Karrer G.
Published: November 2007

Gentiana cachemirica is a rare plant from northern Pakistan and northwestern India. The sectional position of this species has been a matter of considerable debate. Various authors have placed Gentiana cachemirica in one of three different sections – Gentiana sect. Isomeria, Gentiana sect. Kudoa or Gentiana sect. Pneumonanthe. The present paper assesses the taxonomic affinities of this species using a detailed study of its morphology accompanied by morphological phylogenetic and cluster analyses. Characters of the seed testa, corolla morphology and growth architecture were studied for selected species from the above-mentioned sections and closely related Gentiana sect. Cruciata. Representatives of Gentiana sect. Ciminalis were used as outgroups. Our results suggest that G. cachemirica belongs to Gentiana sect. Pneumonanthe and that its affinities are closer to the Western Asiatic group of this section.
NOTES ON THE TAXONOMY OF GIRGENSOHNIA (CHENOPODIACEAE / AMARANTHACEAE)
Authors: Sukhorukov A. P.
Published: November 2007

An overview is given of Girgensohnia (Chenopodiaceae/Amaranthaceae). Five species are recognized including one new species, Girgensohnia bungeana Sukhor. A key for identifying species is provided together with details of their distribution. Lectotypes for the following names are chosen: Girgensohnia diptera Bunge, Girgensohnia oppositiflora (Pall.) Fenzl, Anabasis heteroptera Jaub. & Spach (= Girgensohnia heteroptera (Jaub. & Spach) Bunge), Girgensohnia imbricata Bunge and Girgensohnia pallasii Bunge (= Girgensohnia oppositiflora (Pall.) Fenzl).
A NEW SPECIES IN THE GENUS HEDYOTIS (RUBIACEAE) FROM SOUTH CHINA
Authors: Chen Tao
Published: November 2007

A new species of Rubiaceae, Hedyotis shenzhenensis T.Chen, from Shenzhen, South China, is described and illustrated.
Flowering Plant Families of the World (2nd edition). V. H. Heywood, R. K. Brummitt, A. Culham & O. Sedberg.
Authors: Kiew R.
Published: November 2007

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Pathogenesis of infantile haemangioma: new molecular and cellular insights
Authors: Ritter Matthew R. , Butschek Ross A. , Friedlander Martin , Friedlander Sheila F.
Published: November 2007

Infantile haemangioma is the most common tumour of infancy, yet the origin of these lesions remains controversial and the predictable life cycle is poorly understood. Much new information on infantile haemangiomas has emerged over the past decade, but experts continue to debate fundamental features, including cell of origin, nonrandom distribution, and mechanisms regulating the sometimes explosive growth and slow involution. The development of useful laboratory models has been difficult, in turn restricting the development of treatment options available to the clinician. Despite this, new research and creative thinking has spawned several hypotheses on the origin of these tumours and their interesting clinical behaviour, including suggestions of an intrinsic defect in local endothelial cells, a contribution of circulating endothelial progenitors or haemangioblasts, embolisation of shed placental cells and developmental field defects. While no single hypothesis seems to describe all features of infantile haemangioma, continued research seeks to integrate these ideas, create a better understanding of these important tumours and bring new treatments to the clinic.
Gewichtsverlust und Nachtschweiss mit unerwarteter Tumorlokalisation
Authors: Oberholzer  , Sawatzki  , Rothermundt
Published: November 2007

Wir berichten über einen 52-jährigen Patienten mit Gewichtsverlust und Nachtschweiss, bei den Laboranalysen fielen eine stark erhöhte Blutsenkung, erhöhte Immunglobuline und eine Anämie mit Geldrollenbildung auf. Differentialdiagnostisch schien ein multiples Myelom oder eine Lymphomerkrankung vorzuliegen. Auch eine HIV-Infektion war differentialdiagnostisch möglich, zumal eine entsprechende Risikokonstellation vorlag und der Patient einen Mundsoor aufwies. Urinstatus und Thoraxröntgen waren unauffällig, mittels Computertomographie wurde jedoch die Diagnose eines pulmonal metastasierenden Nierenzellkarzinoms gestellt. Nierenzellkarzinome können sich klinisch sehr vielfältig präsentieren und werden meist spät entdeckt, da spezifische Symptome fehlen. Nierenzellkarzinome führen nicht selten zu paraneoplastischen Syndromen, wie z.B. Hyperkalzämie und Hypertonie.
Ground deformations in the Island of Pantelleria (Italy): Insights into the dynamic of the current intereruptive period
Authors: Mattia M. , Bonaccorso A. , Guglielmino F.
Published: November 2007

The Island of Pantelleria, located between the coasts of Sicily (Italy) and Tunisia, is deforming due to volcanic and tectonic activity. Here we use electro‐optical distance meter, leveling, GPS, and differential interferometry synthetic aperture radar data to constrain the inter‐eruptive deformation pattern. We observe subsidence affecting the main caldera of Pantelleria, in the central southern sector of the island. Subsidence is mainly related to hydrothermal cooling and/or fluid withdrawal from a shallow (4 km below sea level) magma chamber located beneath the caldera. The relationships between the caldera area and the remnant part of the island are also investigated through a review of petrographic, geochemical, and structural data.
Relationship between capillary pressure, saturation, and interfacial area from a model of mixed‐wet triangular tubes
Authors: Helland J. O. , Skjæveland S. M.
Published: November 2007

A simple bundle of triangular tubes model is employed to calculate specific interfacial area for primary drainage, imbibition, and secondary drainage for mixed‐wet conditions. In this model, only the interfaces between bulk and corner fluid are contributory to the interfacial area. Accurate expressions for the capillary entry pressures are employed, which account for the possibility of hinging interfaces in the corners due to contact angle hysteresis. The results show that very different trends in the specific interfacial area versus saturation curves can occur during imbibition, depending on the advancing contact angle and the reversal point after primary drainage. For water‐wet conditions, interfacial area scanning curves coincide with the bounding imbibition curve, while for oil‐wet conditions, the scanning curves may cross each other because of the impact that hinging interfaces in the pore corners have on the invasion order of the pore sizes. Analytical expressions for specific interfacial area as a function of saturation and capillary pressure are derived for primary drainage of triangular tubes. Approximate correlations for interfacial area as a function of saturation are suggested for the subsequent imbibition and drainage processes. The correlations are fitted to the simulated data, and good agreement is obtained. We also demonstrate that hysteresis remains present in the relationship between interfacial area, capillary pressure, and saturation when contact angle hysteresis is assumed. Hysteresis may be significant for both water‐wet and mixed‐wet conditions. A more sophisticated model is required to examine if this is also the case when hysteresis is caused by phase entrapment.
A mineralogical model for density and elasticity of the Earth's mantle
Authors: Piazzoni A. S. , Steinle‐Neumann G. , Bunge H.‐P. , Dolejš D.
Published: November 2007

We present a thermodynamic model of high‐pressure mineralogy that allows the evaluation of phase stability and physical properties for the Earth's mantle. The thermodynamic model is built from previous assessments and experiments in the five‐component CFMAS system (CaO‐FeO‐MgO‐Al2O3‐SiO2), including mineral phases that occur close to typical chemical models of the mantle and reasonable mantle temperatures. In this system we have performed a system Gibbs free energy minimization, including pure end‐member phases and a nonideal formulation for solid solutions. Solid solutions were subdivided into discrete pseudocompounds and treated as stoichiometric phases during computation of chemical equilibrium by the simplex method. We have complemented the thermodynamic model with a model of shear wave properties to obtain a full description of aggregate elastic properties (density, bulk, and shear moduli) that provide a useful basis for the consideration of seismic and geodynamic models of the Earth's mantle. The thermodynamic model described here is made available for research and training purposes through a Web interface (http://www.earthmodel.org). We examine its validity in light of experiments from mineral physics and briefly discuss inferences for mantle structure.
Link between European and North Atlantic abrupt climate changes over the last glaciation
Authors: Rousseau Denis‐Didier , Sima Adriana , Antoine Pierre , Hatté Christine , Lang Andreas , Zöller Ludwig
Published: November 2007

Sub‐millennial timescale climate variations correlated with those in the North Atlantic area are identified in the loess sequence from Nussloch, Germany, exceptionally developed over the interval between about 38,000 and 18,000 years ago. The Dansgaard‐Oeschger (DO) events 8 to 2, as well as some less pronounced warming episodes recorded in the Greenland ice have their counterpart in the Nussloch loess stratigraphy and in the variations of the loess grain‐size index (GSI). The North Atlantic Heinrich events 3 and 2 are expressed at Nussloch as maxima of the GSI record. The similarity of the fine variations in the Nussloch loess and the Greenland ice records points to an intimate link of climate changes in Western Europe with those in the North Atlantic.