bluuebunny/crossref_metadata_2025 huggingface dataset:
40 years of Physica Scripta
Authors: Wäppling Roger
Published: January 2010

Physica Scripta is an international journal published by the Royal Swedish Academy of Sciences since 1970. It covers all aspects of physics and is one of the few general (broadband) physics journals still around that publishes 'full-length' research papers.

The involvement of the Royal Swedish Academy of Sciences in scientific publication began in 1903 with Arkiv för matematik, astronomi och fysik. This journal collected results in the fields of mathematics, astronomy and physics. In 1949 it was divided into four independent journals: Arkiv för astronomi, Arkiv för fysik, Arkiv för geofysik and Arkiv för matematik. Subsequently, a total of 40 volumes of Arkiv för fysik were published until its replacement by Physica Scripta in 1970.

When Physica Scripta was started, the emphasis was on articles contributed from the Scandinavian countries, including Finland. These restrictions on submissions became further evident when other Nordic science academies and physical societies were invited to participate in the publication process.

Nowadays, the main journal, published in 12 monthly issues, carries the subtitle 'An international journal for experimental and theoretical physics' and is a truly international journal both in terms of circulation and of submitted and published articles. The contributions from the Nordic countries are now only a small part of the total published material.

An experiment in 1974, publishing the proceedings of a Nobel Physics Symposium, led to the formation of a semi-independent journal, Physica Scripta Topical Issues (PSTOP). To date, over 138 volumes of PSTOPs have been published, mostly containing conference proceedings covering a wide range of topics. The annual Nobel Physics Symposium is usually published as one of these volumes.
Beginning in 2003, Physica Scripta introduced a new section, Comments on Atomic and Molecular Physics. This has since expanded to five distinct sections of Comments: atomic, molecular and optical physics (CAMOP); condensed matter physics (CCMP); nuclear and particle physics (CNPP); plasma physics and controlled fusion (CPPCF); astrophysics and cosmology (CAC). These sections contain invited papers that provide an authoritative contribution by an acknowledged expert and are intended to provide insight into current problems, methods and results.

In the publication process we collaborate with IOP Publishing, which ensures a fast and efficient manuscript management system and journal production, with both online and printed volumes.

In 2010 Physica Scripta celebrates 40 years of successful publishing and we encourage physicists throughout the world to join us in celebrating this prestigious anniversary by submitting their contributions.
High Resolution Crossed Beams Scattering Study of the F+HDDF+H Reaction
Authors: Wang Xing-an , Che Li , Ren Ze-feng , Qiu Ming-hui , Dai Dong-xu , Wang Xiu-yan , Yang Xue-ming
Published: January 2010

Crossed beams scattering study was carried out on the F+HDDF+H reaction using high-resolution H-atom Rydberg tagging time-of-flight technique. Vibrational state-resolved differential cross sections were measured, with partial rotational state resolution, at eight collision energies in the range of 2.515.60 kJ/mol. Experimental results indicated that the product angular distributions are predominantly backward scattered. As the collision energy increases, the backward scattered peak becomes broader gradually. Dependence of product vibration branching ratios on the collision energy was also determined. The experimental results show that the DF products are highly inverted in the vibrational state distribution and the DF (v = 3) product is the most populated state. Furthermore, the DF (v = 1) product has also been observed at collision energy above 3.97 kJ/mol.
Infrared Absorption Intensity Analysis as a New Tool for Investigation of Salt Effect on Proteins
Authors: Li Heng , Xu Yan-yan , Weng Yu-xiang
Published: January 2010

The native protein structures in buffer solution are maintained by the electrostatic force as well as the hydrophobic force, salt ions play an important role in maintaining the protein native structures, and their effect on the protein stability has attracted tremendous interests. Infrared spectroscopy has been generally used in molecular structure analysis due to its fingerprint resolution for different species including macromolecules as proteins. However spectral intensities have received much less attention than the vibrational frequencies. Here we report that the spectral intensities of protein amide I band, the finger prints for the protein secondary structures, are very sensitive to the local electric field known as Onsager reaction field caused by salt ions. IR absorbance thermal titrations have been conducted for a series of samples including simple water soluble amino acids, water soluble monomeric protein cytochrome c and dimeric protein DsbC and its single-site mutant G49R. We found that at lower temperature range (1020 C), there exists a thermal activated salting-in process, where the IR intensity increases with a rise in the temperature, corresponding to the ions binding of the hydrophobic surface of protein. This process is absent for the amino acids. When further raising the temperature, the IR intensity decreases, this is interpreted as the thermal activated breaking of the ion-protein surface binding. Applying Van't Hoff plot to the thermal titration curves, the thermodynamic parameters such as H and S for salting-in and ion unbinding processes can be derived for various protein secondary structural components, revealing quantitatively the extent of hydrophobic interaction as well as the strength of the ion-protein binding.
Anharmonic Vibrational Signatures of DNA Bases and WatsonCrick Base Pairs
Authors: Wang Gui-xiu , Ma Xiao-yan , Wang Jian-ping
Published: January 2010

Changes of molecular structure and associated charge distributions, and changes of anharmonic vibrational parameters from DNA base monomers to the WatsonCrick base pairs, have been investigated at the density functional theory level. Through examination of the NH2, NH, and C = O stretching vibrational modes that are involved in the multiple H-bonds in the base pairs, sensitivity of their diagonal and off-diagonal anharmonicities, as well as anharmonic vibrational couplings, to the structure change are predicted. Our results reveal the intrinsic connection between the anharmonic vibrational potentials, H-bonding, and electrostatic interactions in DNA bases.
Laser-induced Alignment and Coulomb Explosion of CO2
Authors: Wu Cheng-yin , Jiang Hong-yan , Wu Zhi-feng , Gong Qi-huang
Published: January 2010

Dynamic processes of CO2 are experimentally studied in intense femtosecond laser fields with laser intensity varying from 1 1013 W/cm2 to 6 1014 W/cm2. When the laser intensity is below the ionization threshold, a coherent rotational wave-packet is formed for CO2 at room temperature through nonadiabatic rotational excitation. The evolution of the wave-packet leads to transient alignment. The field-free alignment revives periodically after the laser pulse is over. The revival structure can be modified by a second laser pulse for the rotational wave-packet through precisely adjusting the time delays between the two laser pulses. When the laser intensity excesses the ionization threshold, ionization and Coulomb explosion occur. The atomic ions Cm+ (m = 13) and On+ (n = 13) observed in the experiment exhibit highly anisotropic angular distributions relative to the laser polarization. Using two linearly polarized laser pulses with crossed polarization, we conclude that the anisotropic angular distribution results from dynamic alignment, in which the rising edge of the laser pulse aligns the neutral CO2 along the laser polarization direction prior to ionization.
DFT Calculation of Glycine with Methanols Clusters
Authors: Zou Hao , Hu Yong-jun , Xing Da
Published: January 2010

Density functional theory (DFT) calculations are reported for the structures of neutral and zwitterionic glycine-(CH3OH)n where n = 16. Initial geometries of the clusters of neutral and zwitterionic glycine with 16 methanol molecules are fully optimized at B3LYP/631+G* level of theory. The lowest energy configurations are located and their hydrogen bond structures are analyzed. Theoretical prediction reveals that the methanols prefer to locate near the carboxylic acid group for the small clusters (n 3) with the neutral form while the configurations with the methanols bridging the acid and the amino group are favorite in the zwitterionic form clusters. When the number of the methanol molecules in the clusters reaches five and six, the two forms tend to be isoenergetic.
Wavelength-dependent Photodissociation Dynamics of Benzaldehyde
Authors: Liu Ben-kang , Wang Bing-xing , Wang Yan-qiu , Wang Li
Published: January 2010

The ultrafast dynamics of benzaldehyde upon 260, 271, 284, and 287 nm excitations have been studied by femtosecond pump-probe time-of-flight mass spectrometry. A bi-exponential decay component model was applied to fit the transient profiles of benzaldehyde ions and fragment ions. At the S2 origin, the first decay of the component was attributed to the internal conversion to the high vibrational levels of S1 state. Lifetimes of the first component decreased with increasing vibrational energy, due to the influence of high density of the vibrational levels. The second decay was assigned to the vibrational relaxation of the S1 whose lifetime was about 600 fs. Upon 287 nm excitation, the first decay became ultra-short (56 fs) which was taken for the intersystem cross from S1 to T2, while the second decay component was attributed to the vibrational relaxation. The pump-probe transient of fragment was also studied with the different probe intensity at 284 nm pump.
Quantitative Surface Chirality Detection with Sum Frequency Generation Vibrational Spectroscopy: Twin Polarization Angle Approach
Authors: Wei Feng , Xu Yan-yan , Guo Yuan , Liu Shi-lin , Wang Hong-fei
Published: January 2010

Here we report a novel twin polarization angle (TPA) approach in the quantitative chirality detection with the surface sum-frequency generation vibrational spectroscopy (SFG-VS). Generally, the achiral contribution dominates the surface SFG-VS signal, and the pure chiral signal is usually two or three orders of magnitude smaller. Therefore, it has been difficult to make quantitative detection and analysis of the chiral contributions to the surface SFG-VS signal. In the TPA method, by varying together the polarization angles of the incoming visible light and the sum frequency signal at fixed s or p polarization of the incoming infrared beam, the polarization dependent SFG signal can give not only direct signature of the chiral contribution in the total SFG-VS signal, but also the accurate measurement of the chiral and achiral components in the surface SFG signal. The general description of the TPA method is presented and the experiment test of the TPA approach is also presented for the SFG-VS from the S- and R-limonene chiral liquid surfaces. The most accurate degree of chiral excess values thus obtained for the 2878 cm1 spectral peak of the S- and R-limonene liquid surfaces are (23.7 0.4)% and (25.4 1.3)%, respectively.
Newab initioPotential Energy Surfaces for Cl(2P3/2, 2P1/2)+H2 Reaction
Authors: Jiang Bin , Xie Dai-qian
Published: January 2010

New global three dimensional potential energy surfaces for the Cl+H2 reactive system have been constructed using accurate multireference configuration interaction calculations with a large basis set. The three lowest adiabatic potential energy surfaces correlating asymptotically with Cl(2P)+H2 have been transformed to a diabatic representation, which leads to a fourth coupling potential for non-linear geometries. In addition, the spin-orbit coupling surfaces have also been computed using the BreitPauli Hamiltonian. Properties of the new potential are described. Reaction dynamics based on the new potential agrees with the recent experimental results quite well.
Corona Discharge Ion Mobility Spectrometry of Ten Alcohols
Authors: Han Hai-yan , Wang Hong-mei , Jiang Hai-he , Stano Michal , Sabo Martin , Matejcik Stefan , Chu Yan-nan
Published: January 2010

Ion mobility spectra for ten alcohols have been studied in an ion mobility spectrometry apparatus equipped with a corona discharge ionization source. Using protonated water cluster ions as the reactant ions and clean air as the drift gas, the alcohols exhibit different product ion characteristic peaks in their ion mobility spectra. The detection limit for these alcohols is at low concentration pmol/L level according to the concentration calibration by exponential dilution method. Based on the measured ion mobilities, several chemical physics parameters of the ion-molecular interaction at atmosphere were obtained, including the ionic collision cross sections, diffusion coefficients, collision rate constants, and the ionic radii under the hard-sphere model approximation.
Cavity Ring Down Laser Absorption Spectroscopy of NiI
Authors: Ma Tong-mei , Li Ling , Wing Har Leung Joanne , Shi Chung Cheung Allan
Published: January 2010

The absorption spectrum of NiI between 445 and 510 nm has been investigated using the technique of laser vaporization/reaction with free jet expansion and cavity ring down laser absorption spectroscopy. Two new transitions namely, [21.3]25/2-X25/2 and [21.9]23/2-X25/2 systems were identified and studied. Spectra of both 58NiI and 60NiI isotopic molecules were observed. Equilibrium molecular constants for both electronic states are reported and the equilibrium bond length for the [21.3]25/2 state and the [21.9]23/2 state was respectively determined to be 2.431 and 2.481 A.
Measurement of Photoionization Cross Sections of the Excited States of Titanium
Authors: Yang Jia-jun , Hu Xing-yong , Wu Hong-xia , Fan Jian-mei , Cong Ran , Cheng Yi , Ji Xue-han , Yao Guan-xin , Zheng Xian-feng , Cui Zhi-feng
Published: January 2010

Resonance-enhanced multiphoton ionization of the titanium atoms has been investigated in the 293321 nm wavelength. We couple a laser-ablated metal target into a molecular beam to produce free atoms. Ions produced from photoionization of the neutral atoms are monitored by a home-built time-of-flight mass spectrometer. Photoionization cross sections of the excited states of Ti I were deduced from the dependence of the ion signal intensity on the laser intensity for photon energies close to the ionization threshold. The values obtained range from 0.2 Mb to 6.0 Mb. No significant isotope-dependence was found from measurements of the photoionization cross sections of 46Ti, 47Ti, and 48Ti.
Molecular Axis Orientation in Charge Transfer Reactions Determined with a Reaction Microscope
Authors: Zhang Shao-feng , Ma Xin-wen , Zhu Xiao-long
Published: January 2010

Based on the reaction microscope at the institute of modern physics, the reaction mechanism in molecular ion-atom collisions is investigated experimentally. The features of this system is illustrated by a kinematically complete experiment performed for the collision process. Using the so-called list-mode data recording technique and the coincidence measurement, the momentum vector of each fragment from the molecular ion were recorded event by event. The orientation of the molecular axis for H2+ dissociation reactions could be determined for each event in the off-line analysis. The measured orientation of the molecular ion is believed the same as the one at the instance of collision under axial recoil approximation. The polar angle resolution of the molecular orientation of 8 was obtained.
Molecular Dynamics Simulation on Stability of Insulin on Graphene
Authors: Liang Li-jun , Wang Qi , Wu Tao , Shen Jia-wei , Kang Yu
Published: January 2010

The adsorption dynamics of a model protein (the human insulin) onto graphene surfaces with different sizes was investigated by molecular dynamics simulations. During the adsorption, it has different effect on the stability of the model protein in the fixed and non-fixed graphene systems. The tertiary structure of the protein was destroyed or partially destroyed, and graphene surfaces shows the selective protection for some -helices in non-fixed systems but not in fixed systems by reason of the flexibility of graphene. As indicated by the interaction energy curve and trajectory animation, the conformation and orientation selection of the protein were induced by the properties and the texture of graphene surfaces. The knowledge of protein adsorption on graphene surfaces would be helpful to better understand stability of protein on graphene surfaces and facilitate potential applications of graphene in biotechnology.
Experimental and Theoretical Study of Hydrogen Atom Abstraction from Ethylene by Stoichiometric Zirconium Oxide Clusters
Authors: Wu Xiao-nan , Zhao Yan-xia , He Sheng-gui , Ding Xun-lei
Published: January 2010

The reactions of cationic zirconium oxide clusters (ZrxOy+) with ethylene (C2H4) were investigated by using a time-of-flight mass spectrometer coupled with a laser ablation/supersonic expansion cluster source. Some hydrogen containing products (ZrO2)xH+(x = 14) were observed after the reaction. The density functional theory calculations indicate that apart from the common oxygen transfer reaction channel, the hydrogen abstraction channel can also occur in (ZrO2)x++C2H4, which supports that the observed (ZrO2)xH+ may be due to (ZrO2)x++C2H4(ZrO2)xH++C2H3. The rate constants of different reaction channels were also calculated by Rice-Ramsberger-Kassel-Marcus theory.
Electron Momentum Distributions for 4a1 Orbitals of CFxCl4xin Low Momentum Region: a Possible Evidence of Molecular Geometry Distortion
Authors: Shan Xu , Xu Chun-kai , Yin Xiao-feng , Zhou Li-xia , Xu Ke-zun , Chen Xiang-jun
Published: January 2010

Electron momentum distributions for 4a1 orbitals of serial freon molecules CF3Cl, CF2Cl2, and CFCl3 (CFxCl4x, x = 13) have been reanalyzed due to the severe discrepancies between theory and experiment in low momentum region. The tentative calculations using equilibrium geometries of molecular ions have exhibited a great improvement in agreement with the experimental data, which suggests that the molecular geometry distortion may be responsible for the observed high intensities at p 0.5 a.u. Further analyses show that the severe discrepancies at low momentum region mainly arise from the influence of molecular geometry distortion on CCl bonding electron density distributions.
Mass-analyzed Threshold Ionization Spectroscopy of Rotamers ofp-ethoxyphenol Cations and Configuration Effect
Authors: Zheng Qiu-sha , I Fang Teng , Zhang Bing , Bih Tzeng Wen
Published: January 2010

Two-color resonant two-photon mass-analyzed threshold ionization (MATI) spectroscopy was used to record the vibrationally resolved cation spectra of the selected rotamers of p-ethoxyphenol. The adiabatic ionization energies of the trans and cis rotamers are determined to be 61565 5 and 61670 5 cm1, which are less than that of p-methoxyphenol by 645 and 643 cm1, respectively. Analysis on the MATI spectra of the selected rotamers of p-ethoxyphenol cation shows that the relative orientation of the ethoxy group has little effect on the in-plane ring vibrations. The low-frequency OC2H5 bending vibrations appear to be active for both forms of the cation.
Modification of Reflectron Time-of-Flight Mass Spectrometer for Photodissociation of Mass-Selected Cluster Ions
Authors: Zhao Yu-chao , Zhang Zeng-guang , Yuan Jin-yun , Xu Hong-guang , Zheng Wei-jun
Published: January 2010

We introduce a modification of reflectron time-of-flight mass spectrometer for laser photodissociation of mass-selected ions. In our apparatus, the ions of interests were selected by a mass gate near the first space focus point and decelerated right after the mass gate, were then crossed by a laser beam for dissociation. The daughter ions and surviving parent ions were re-accelerated and analyzed by the reflectron time-of-flight mass spectrometer. Compared to the designs reported by other research groups, our selection-deceleration-dissociation-reacceleration approach has better daughter-parent-ions-separation, easier laser timing, and better overlapping between the ion beam and laser beam. We also conducted detailed calculations on the parent ion and daughter ion flight times, and provided a simplified formula for the calibration of daughter ion mass.
C2H2 Overtones Near 12300 cm1 Revisited with a Very Sensitive Cavity Ring-down Spectrometer
Authors: Gao Bo , Liu An-wen , Wu Rui-xue , Ning Wei , Hu Shui-ming
Published: January 2010

A cavity ring-down spectrometer (CRDS) is constructed with a single-mode continuous-wave Ti: Sapphire laser. It allows attaining a minimum detectable absorption of 1.8 1010 cm1. The spectrometer is applied to record the overtone spectrum of 12C2H2 in the 1224012350 cm1. Compared with the previous CRDS and intra-cavity laser absorption spectroscopy studies in the same region, the present measurement achieved better sensitivity and better precision as well. As a result, the ro-vibrational parameters of the high overtone bands of acetylene at 12290.12, 12311.82, and 12350.61 cm1 have been refined. The advantages of the present CRD spectrometer is also demonstrated by the newly observed and well characterized perturbation on the f component of the very weak band near 12289 cm1. The quantitative measurement capability of the spectrometer is verified with the measurement of the water lines and employed to give the absolute band intensities of those three acetylene bands.
Laser-induced Fluorescence Excitation Spectrum of NiS in 1550017200 cm1
Authors: Zhen Jun-feng , Wang Li , Qin Cheng-bing , Zhang Qun , Chen Yang
Published: January 2010

The laser-induced fluorescence excitation spectrum of jet-cooled NiS molecule has been recorded in the energy range of 1550017200 cm1. Fifteen bands have been assigned as three transition progressions: [15.65]31(v = 04)-X30(v = 0), [15.69]30(v = 04)-X30(v = 0), and [15.81]31(v = 04)-X30(v = 0). Spectroscopic constants for the three newly identified electronically excited states have been determined for the first time. In addition, the lifetimes for most observed vibronic bands have also been measured.
Reaction of C2HCl2+O2: Combined TR-FTIR Spectroscopy and Electronic Structure
Authors: Xiang Tian-Cheng , Wang Huan , Liu Kun-hui , Zhao Hong-mei , Wu Wei-qiang , Su Hong-mei
Published: January 2010

The product channels and mechanisms of the C2HCl2+O2 reaction are investigated by step-scan time-resolved Fourier transform infrared emission spectroscopy and the G3MP2//B3LYP/6311G(d,p) level of electronic structure calculations. Vibrationally excited products of HCl, CO, and CO2 are observed in the IR emission spectra and the product vibrational state distribution are determined which shows that HCl and CO are vibrationally excited with the nascent average vibrational energy estimated to be 59.8 and 51.8 kJ/mol respectively. In combination with the G3MP2//B3LYP/6311G(d,p) calculations, the reaction mechanisms have been characterized and the energetically favorable reaction pathways have been suggested.
Detection of OH Radical in the Photodissociation ofp-Aminobenzoic Acid at 266 nm
Authors: Zhou Can-hua , Cheng Shi-bo , Yin Hong-ming , He Guo-zhong
Published: January 2010

Photodissociation of p-aminobenzoic acid at 266 nm was investigated by probing the nascent OH photoproduct employing the laser-induced fluorescence technique. It was found that the nascent OH radical was vibrationally cold and its rotational state distribution conformed to be a Boltzmann behavior, characterized by a rotational temperature of 1040 110 K. The rotational energy of OH was determined to be 8.78 0.84 kJ/mol. Between the two spin-orbit states of OH, 23/2 and 21/2, the former was found to be preferentially populated. The distribution of the (A) state for the -doublet was dominant. Finally, a probable mechanism for the formation of OH produced from the photodissociation of p-aminobenzoic acid is discussed.
PyRosetta: a script-based interface for implementing molecular modeling algorithms using Rosetta
Authors: Chaudhury Sidhartha , Lyskov Sergey , Gray Jeffrey J.
Published: January 2010

Summary: PyRosetta is a stand-alone Python-based implementation of the Rosetta molecular modeling package that allows users to write custom structure prediction and design algorithms using the major Rosetta sampling and scoring functions. PyRosetta contains Python bindings to libraries that define Rosetta functions including those for accessing and manipulating protein structure, calculating energies and running Monte Carlo-based simulations. PyRosetta can be used in two ways: (i) interactively, using iPython and (ii) script-based, using Python scripting. Interactive mode contains a number of help features and is ideal for beginners while script-mode is best suited for algorithm development. PyRosetta has similar computational performance to Rosetta, can be easily scaled up for cluster applications and has been implemented for algorithms demonstrating protein docking, protein folding, loop modeling and design.

Availability: PyRosetta is a stand-alone package available at http://www.pyrosetta.org under the Rosetta license which is free for academic and non-profit users. A tutorial, user's manual and sample scripts demonstrating usage are also available on the web site.

Contact:  pyrosetta@graylab.jhu.edu
Fuelling the decline in UK fishing communities?
Authors: Abernethy Kirsten E. , Trebilcock Paul , Kebede Bereket , Allison Edward H. , Dulvy Nicholas K.
Published: January 2010

Abernethy, K. E., Trebilcock, P., Kebede, B., Allison, E. H., and Dulvy, N. K. 2010. Fuelling the decline in UK fishing communities? – ICES Journal of Marine Science, 67: 1076–1085. Volatile fuel prices are a threat to the viability of UK fishing communities. The economic and social impacts of rising fuel costs for fishers and communities in southwest England are examined. Fuel prices doubled between early 2007 and mid-2008, whereas fish prices remained relatively stable throughout as a result of the price-setting power of seafood buyers. It was the fishers who absorbed the increased costs, resulting in significant loss of income, reduced job security, and problems in recruiting crew. All gear types were affected, but fishers using towed gears were most adversely impacted. Fishing vessels with recent investment have greater fuel efficiency, so appeared to be more able to cope and to adapt to increased fuel costs. Fishing behaviour also altered as skippers attempted to increase fuel efficiency at the cost of reduced catches. Most skippers reported fishing closer to port, reducing their exploratory fishing, and ceasing experimentation with fishing gears with lesser environmental impact. Therefore, a threat to fishing community viability may have linked environmental effects. The impacts of this fuel price volatility foreshadow a likely future impact of rising fuel prices attributable to climate change adaptation and mitigation and forecasts of rising oil prices. Without proactive planning and policy development, rising fuel prices have the potential to cause job losses and economic hardship additional to problems that may arise from poor management and stock decline, in all fishing-related sectors of the industry.
Problem-Solving Skills Training for Vulnerable Families of Children with Persistent Asthma: Report of a Randomized Trial on Health-Related Quality of Life Outcomes
Authors: Seid Michael , Varni James W. , Gidwani Pradeep , Gelhard Leticia Reyes , Slymen Donald J.
Published: January 2010

Objectives To test the efficacy of problem-solving skill training (PST) in improving health-related quality of life (HRQOL) of children with persistent asthma from predominantly lower socioeconomic status (SES) Spanish-speaking Hispanic families. Methods Randomized controlled trial comparing standard care waitlist (SC) control, home-visiting asthma education/care coordination (CC), and combined intervention (CC + PST) at baseline, after intervention, and 6-month follow-up. The primary outcome was parent proxy-report child HRQOL (PedsQL). Results Participants (n = 252) were 83.3% Hispanic and 56.3% monolingual Spanish speakers, and 72.6% of mothers had not graduated high school. We found a significant (P = 0.05) intervention effect for parent proxy-reported child generic (but not asthma-specific) HRQOL, with CC + PST superior to SC [83.8 vs 79.8; adjusted mean difference of 4.05 points (95% confidence interval 0.63–7.4], but no difference between the CC and SC groups. Conclusions In this sample of vulnerable families of children with persistent asthma, a CC + PST intervention was efficacious in improving children’s generic HRQOL.
Pseudomonas syringae Strains Naturally Lacking the Classical P. syringae hrp/hrc Locus Are Common Leaf Colonizers Equipped with an Atypical Type III Secretion System
Authors: Clarke Christopher R. , Cai Rongman , Studholme David J. , Guttman David S. , Vinatzer Boris A.
Published: January 2010

Pseudomonas syringae is best known as a plant pathogen that causes disease by translocating immune-suppressing effector proteins into plant cells through a type III secretion system (T3SS). However, P. syringae strains belonging to a newly described phylogenetic subgroup (group 2c) are missing the canonical P. syringae hrp/hrc cluster coding for a T3SS, flanking effector loci, and any close orthologue of known P. syringae effectors. Nonetheless, P. syringae group 2c strains are common leaf colonizers and grow on some tested plant species to population densities higher than those obtained by other P. syringae strains on nonhost species. Moreover, group 2c strains have genes necessary for the production of phytotoxins, have an ice nucleation gene, and, most interestingly, contain a novel hrp/hrc cluster, which is only distantly related to the canonical P. syringae hrp/hrc cluster. This hrp/hrc cluster appears to encode a functional T3SS although the genes hrpK and hrpS, present in the classical P. syringae hrp/hrc cluster, are missing. The genome sequence of a representative group 2c strain also revealed distant orthologues of the P. syringae effector genes avrE1 and hopM1 and the P. aeruginosa effector genes exoU and exoY. A putative life cycle for group 2c P. syringae is discussed.
Rational spatio-temporal strategies for controlling a Chagas disease vector in urban environments
Authors: Levy Michael Z. , Malaga Chavez Fernando S. , Cornejo del Carpio Juan G. , Vilhena Daril A. , McKenzie F. Ellis , Plotkin Joshua B.
Published: January 2010

The rational design of interventions is critical to controlling communicable diseases, especially in urban environments. In the case of the Chagas disease vectorTriatoma infestans, successful control is stymied by the return of the insect after the effectiveness of the insecticide wanes. Here, we adapt a genetic algorithm, originally developed for the travelling salesman problem, to improve the spatio-temporal design of insecticide campaigns againstT. infestans, in a complex urban environment. We find a strategy that reduces the expected instances of vector return 34-fold compared with the current strategy of sequential insecticide application to spatially contiguous communities. The relative success of alternative control strategies depends upon the duration of the effectiveness of the insecticide, and it shows chaotic fluctuations in response to unforeseen delays in a control campaign. We use simplified models to analyse the outcomes of qualitatively different spatio-temporal strategies. Our results provide a detailed procedure to improve control efforts for an urban Chagas disease vector, as well as general guidelines for improving the design of interventions against other disease agents in complex environments.
Multiple solutions for a class of
p
(
x
)-Laplacian equations in involving the critical exponent
Authors: Fu Yongqiang , Zhang Xia
Published: January 2010

In this paper, we first establish a principle of concentration compactness in

. Then, based on this concentration compactness principle, we study the existence of solutions for a class of
p
(
x
)-Laplacian equations in

involving the critical exponent. Under suitable assumptions, we obtain a sequence of radially symmetric solutions associated with a sequence of positive energies going towards infinity.
Sensitivity of the macroscopic response of elastic microstructures to the insertion of inclusions
Authors: Giusti Sebastián M. , Novotny Antonio A. , de Souza Neto Eduardo A.
Published: January 2010

This paper proposes an exact analytical formula for the topological sensitivity of the macroscopic response of elastic microstructures to the insertion of circular inclusions. The macroscopic response is assumed to be predicted by a well-established multi-scale constitutive theory where the macroscopic strain and stress tensors are defined as volume averages of their microscopic counterpart fields over a representative volume element (RVE) of material. The proposed formula—a symmetric fourth-order tensor field over the RVE domain—is a topological derivative which measures how the macroscopic elasticity tensor changes when an infinitesimal circular elastic inclusion is introduced within the RVE. In the limits, when the inclusion/matrix phase contrast ratio tends to zero and infinity, the sensitivities to the insertion of a hole and a rigid inclusion, respectively, are rigorously obtained. The derivation relies on the topological asymptotic analysis of the predicted macroscopic elasticity and is presented in detail. The derived fundamental formula is of interest to many areas of applied and computational mechanics. To illustrate its potential applicability, a simple finite element-based example is presented where the topological derivative information is used to automatically generate a bi-material microstructure to meet pre-specified macroscopic properties.
Cosmic strings and superstrings
Authors: Copeland Edmund J. , Kibble T. W. B.
Published: January 2010

Cosmic strings are predicted by many field-theory models, and may have been formed at a symmetry-breaking transition early in the history of the universe, such as that associated with grand unification. They could have important cosmological effects. Scenarios suggested by fundamental string theory or M-theory, in particular the popular idea of brane inflation, also strongly suggest the appearance of similar structures. Here we review the reasons for postulating the existence of cosmic strings or superstrings, the various possible ways in which they might be detected observationally and the special features that might discriminate between ordinary cosmic strings and superstrings.
Pseudomonas chlororaphis subsp. piscium subsp. nov., isolated from freshwater fish
Authors: Burr Sarah E. , Gobeli Stefanie , Kuhnert Peter , Goldschmidt-Clermont Elinor , Frey Joachim
Published: January 2010

Gram-negative, aerobic, motile, rod-shaped bacteria were isolated from the intestines of freshwater fish on two separate occasions. Colonies of both strains, JF3835T and JF4413, produced non-diffusible green pigment following 4–5 days incubation on Luria–Bertani agar. The most abundant fatty acids were summed feature 3 (comprising C16 : 1
ω7c and/or C15 : 0 iso 2-OH), C16 : 0 and C18 : 1
ω7c. The DNA G+C content was 62.9 mol%. Sequence analysis of the 16S rRNA gene indicated 100 % sequence similarity between the two strains. In comparison with recognized species, the new strains exhibited the greatest degree of sequence similarity with members of the Pseudomonas chlororaphis subspecies: P. chlororaphis subsp. chlororaphis (99.84 %), P. chlororaphis subsp. aurantiaca (99.75 %) and P. chlororaphis subsp. aureofaciens (99.40 %). While DNA–DNA relatedness confirmed the placement of strains JF3835T and JF4413 as members of the species P. chlororaphis, multilocus sequencing indicated that the strains formed a distinct cluster within it. On the basis of genotypic and phenotypic evidence, strains JF3835T and JF4413 represent a novel subspecies of the species P. chlororaphis, for which the name Pseudomonas chlororaphis subsp. piscium subsp. nov. is proposed. The type strain is JF3835T (=NCIMB 14478T=DSM 21509T).
Rhodothermus profundi sp. nov., a thermophilic bacterium isolated from a deep-sea hydrothermal vent in the Pacific Ocean
Authors: Marteinsson Viggó Thór , Bjornsdottir Snaedis H. , Bienvenu Nadège , Kristjansson Jakob K. , Birrien Jean-Louis
Published: January 2010

Nine thermophilic strains of aerobic, non-sporulating, heterotrophic bacteria were isolated after enrichment of chimney material sampled from a deep-sea hydrothermal field at a depth of 2634 m on the East-Pacific Rise (1 °N). The bacteria stained Gram-negative. They were rod-shaped and measured approximately 0.5 μm in width and 1.5–3.5 μm in length. They grew at 55–80 °C, pH 6–8 and 1–6 % NaCl. Optimal growth was observed at 70–75 °C, pH 7.0 and 1–3 % NaCl. The organisms were identified as members of the genus Rhodothermus, having a 16S rRNA gene similarity of 98.1 % with Rhodothermus
marinus DSM 4252T. The novel isolates differed morphologically, physiologically and chemotaxonomically from R. marinus, e.g. in lack of pigmentation, response to hydrostatic pressure, maximum growth temperature and DNA G+C content. DNA–DNA hybridization revealed a reassociation value of 37.2 % between strain PRI 2902T and R. marinus DSM 4252T, which strongly suggested that they represent different species. Furthermore, AFLP fingerprinting separated the novel strains from R. marinus reference strains. It is therefore concluded that the strains described here should be classified as representatives of a novel species for which the name Rhodothermus profundi sp. nov. is proposed; the type strain is PRI 2902T (=DSM 22212T =JCM 15944T).
Staphylococcus devriesei sp. nov., isolated from teat apices and milk of dairy cows
Authors: Supré Karlien , De Vliegher Sarne , Cleenwerck Ilse , Engelbeen Katrien , Van Trappen Stefanie , Piepers Sofie , Sampimon Otlis C. , Zadoks Ruth N. , De Vos Paul , Haesebrouck Freddy
Published: January 2010

Ten non-motile, Gram-stain-positive, coagulase-negative staphylococci were isolated from bovine milk and teat apices. All isolates were catalase-positive, with anteiso-C15 : 0, iso-C15 : 0, anteiso-C17 : 0, iso-C17 : 0and C18 : 0as predominant fatty acids and diphosphatidylglycerol and phosphatidylglycerol as major polar lipids. The results of sequence analysis of the 16S rRNA gene and four housekeeping genes (rpoB,hsp60,tufanddnaJ) in combination with tRNA-intergenic spacer length analysis showed that the isolates form a separate branch within the genusStaphylococcus. Based on 16S rRNA gene sequencing, the phylogenetically most closely related species areStaphylococcus haemolyticus,S. hominisandS. lugdunensis, with >98.7 % sequence similarity. The DNA G+C content varies from 33.3 to 33.7 mol%, and DNA–DNA hybridization with the nearest neighbours, based on 16S rRNA gene sequences, confirmed that the isolates represent a novelStaphylococcusspecies. All isolates induced a small zone of complete haemolysis on Columbia agar with 5 % sheep blood and exhibited a homogeneous biochemical fingerprint that is discriminative from the phylogenetically most closely related species. Based on these results, it is proposed to classify the ten isolates asStaphylococcus devrieseisp. nov., with strain KS-SP 60T(=LMG 25332T=CCUG 58238T) as the type strain.
Microbacterium radiodurans sp. nov., a UV radiation-resistant bacterium isolated from soil
Authors: Zhang Wei , Zhu Hong-hui , Yuan Menglong , Yao Qing , Tang Ran , Lin Min , Yang Song-zhen , Li Zhi-kun , Chen Ming
Published: January 2010

Strain GIMN 1.002T, a UV radiation-tolerant bacterium, was isolated from the upper sand layers of the Gobi desert, Xinjiang, China and characterized in order to determine its taxonomic position. Cells were Gram-reaction-positive, heterotrophic, strictly aerobic, short rods. 16S rRNA gene sequence analysis revealed that strain GIMN 1.002T belonged to the genus Microbacterium and was closely related to Microbacterium arborescens DSM 20754T (98.8 % 16S rRNA gene sequence similarity) and Microbacterium imperiale DSM 20530T (98.7 %). However, strain GIMN 1.002T had low DNA–DNA relatedness with M. arborescens DSM 20754T (17.1 %) and M. imperiale DSM 20530T (12.89 %). Strain GIMN 1.002T possessed chemotaxonomic markers that were consistent with its classification in the genus Microbacterium, i.e. MK-11, MK-12 and MK-10 as major menaquinones and anteiso-C15 : 0 (38.67 %), iso-C16 : 0 (18.16 %) and iso-C15 : 0 (17.46 %) as predominant cellular fatty acids. The DNA G+C content was 67.74 mol%. The cell-wall sugar was rhamnose. On the basis of the data from this study, strain GIMN 1.002T represents a novel species of the genus Microbacterium, for which the name Microbacterium radiodurans sp. nov. is proposed. The type strain is GIMN 1.002T (=CCTCC M208212T =NRRL B-24799T).
Saccharofermentans acetigenes gen. nov., sp. nov., an anaerobic bacterium isolated from sludge treating brewery wastewater
Authors: Chen Shuangya , Niu Lili , Zhang Yongxiang
Published: January 2010

A spore-forming anaerobic bacterium, designated strain P6T, was isolated from the sludge of an up-flow anaerobic sludge blanket reactor treating brewery wastewater. Cells were Gram-positive, oval and 0.6–0.9 μm by 1.2–1.8 μm in size. Growth was observed at 20–42 °C and at pH 5.0–7.5. It fermented several hexoses, polysaccharides and alcohols. Sucrose and aesculin could also be fermented. The main end products of fermentation from glucose were acetate, lactate and fumarate; trace CO2 and H2 were also produced. The DNA G+C content of strain P6T was 55.6 mol%. The major cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0 and iso-C14 : 0 3-OH. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain P6T represented a novel phyletic sublineage in clostridial cluster III, and showed <91 % similarity to the type strains of recognized species in this cluster. Phenotypically, the new isolate was distinguished from its phylogenetic relatives (e.g. Clostridium straminisolvens, Clostridium thermocellum, Acetivibrio cellulolyticus and Clostridium aldrichii) by producing acid from glucose and its inability to degrade cellulose. On the basis of evidence from this polyphasic study, strain P6T is considered to represent a novel species of a new genus, for which the name Saccharofermentans acetigenes gen. nov., sp. nov. is proposed. The type strain of Saccharofermentans acetigenes is P6T (=JCM 14006T =AS 1.5064T).
Pseudomonas taeanensis sp. nov., isolated from a crude oil-contaminated seashore
Authors: Lee Dong-Heon , Moon Sung-Ran , Park Young-Hyun , Kim Jung-Ho , Kim Hoon , Parales Rebecca E. , Kahng Hyung-Yeel
Published: January 2010

A novel Gram-negative, aerobic, motile, short rod-shaped bacterium, designated MS-3T, was isolated from a crude oil-contaminated seashore in Taean, Korea. Strain MS-3T grew at 4–30 °C, at pH 6.0–9.5 and with 0–5 % NaCl and was oxidase- and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain MS-3T was most similar to Pseudomonas marincola KMM 3042T (97.9 % 16S rRNA gene sequence similarity), P. cuatrocienegasensis 1NT (97.8 %), P. borbori R-20821T (97.3 %) and P. lundensis ATCC 49968T (97.1 %). Relatively low levels of DNA–DNA relatedness were found between strain MS-3T and P. cuatrocienegasensis LMG 24676T (57.2 %), P. borbori LMG 23199T (39.7 %), P. marincola KMM 3042T (32.2 %) and P. lundensis KACC 10832T (32.1 %), which support the classification of strain MS-3T within a novel species of the genus Pseudomonas. The G+C content of the genomic DNA of strain MS-3T was 57.6 mol% and the major isoprenoid quinone was Q-9. Strain MS-3T contained summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1
ω7c; 38.0 %), C16 : 0 (24.4 %), C18 : 1
ω7c (12.8 %), C12 : 0 (9.6 %) and C10 : 0 3-OH (4.9 %) as the major cellular fatty acids. On the basis of the phenotypic, genotypic and phylogenetic data, strain MS-3T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas taeanensis sp. nov. is proposed. The type strain is MS-3T (=KCTC 22612T =KACC 14032T =JCM 16046T =NBRL 105641T).
Limnohabitans planktonicus sp. nov. and Limnohabitans parvus sp. nov., planktonic betaproteobacteria isolated from a freshwater reservoir, and emended description of the genus Limnohabitans
Authors: Kasalický Vojtěch , Jezbera Jan , Šimek Karel , Hahn Martin W.
Published: January 2010

Two bacterial strains, II-B4T and II-D5T, isolated from the meso-eutrophic freshwater Římov reservoir (Czech Republic), were characterized phenotypically, phylogenetically and chemotaxonomically. Both strains were chemo-organotrophic, facultatively anaerobic, non-motile rods, with identical DNA G+C contents of 59.9 mol%. Their major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine and their major fatty acids were C16 : 1
ω7c/C16 : 1
ω6c, C16 : 0, C18 : 1
ω7c/C18 : 1
ω6c and C12 : 0. Both strains contained Q-8 as the only respiratory quinone component. The 16S rRNA gene sequences of the two strains possessed 99.1 % similarity; however, the level of DNA–DNA reassociation was only 26.7 %. The strains can also be discriminated from each other by several chemotaxonomic and biochemical traits. Phylogenetic analysis of the 16S rRNA gene sequences revealed the affiliation of both strains with the genus Limnohabitans within the family Comamonadaceae. The two investigated strains represent the first isolated members of a narrow phylogenetic cluster (the so-called R-BT065 cluster) formed by a large number of environmental sequences and abundant populations detected in the pelagic zones of various freshwater habitats. We propose to place the two strains in separate novel species within the genus Limnohabitans, Limnohabitans planktonicus sp. nov., with the type strain II-D5T (=DSM 21594T =CIP 109844T), and Limnohabitans parvus sp. nov., with the type strain II-B4T (=DSM 21592T =CIP 109845T). The description of the genus Limnohabitans is emended accordingly.
Pantoea gaviniae sp. nov. and Pantoea calida sp. nov., isolated from infant formula and an infant formula production environment
Authors: Popp Alexandra , Cleenwerck Ilse , Iversen Carol , De Vos Paul , Stephan Roger
Published: January 2010

Five Gram-negative, facultatively anaerobic, non-spore-forming, coccoid rod-shaped bacterial isolates were obtained from infant formula and an infant formula production environment and were investigated by use of a polyphasic taxonomic study. Biochemical tests and partialrpoBgene sequence analysis of the five isolates revealed that they formed two distinct groups in the familyEnterobacteriaceae, closely related to several species of the generaPantoeaandErwinia, which indicated a phylogenetic position within the genusPantoeaor the genusErwinia. Multilocus sequence analysis of concatenated partialatpD,gyrB,infBandrpoBgene sequences of two of the isolates suggested that they represented two novel species of the genusPantoea, phylogenetically related most closely toPantoea septica. The five isolates had general characteristics consistent with those of the genusPantoea, and DNA–DNA hybridizations between two representatives and the type strains of their phylogenetically closest relatives based on comparative 16S rRNA gene sequence analysis showed that the isolates represented two novel genospecies. These two genospecies could be differentiated from each other based on fermentation of galacturonate, sorbitol and potassium 5-ketogluconate. They could be differentiated from phylogenetically relatedPantoeaspecies based on their ability to ferment lactose and to utilizeβ-gentiobiose and raffinose, their inability to ferment or utilized-arabitol, and their inability to produce indole. On the basis of the results obtained, the five isolates are considered to represent two novel species of the genusPantoea, for which the namesPantoea gaviniaesp. nov. (type strain A18/07T=LMG 25382T=DSM 22758T) andPantoea calidasp. nov. (type strain 1400/07T=LMG 25383T=DSM 22759T) are proposed.