bluuebunny/crossref_metadata_2025 huggingface dataset:
Firearms – Ammunition
Authors: Heard Brian J.
Published: September 2011

Firearms Ammunition, Basic Terminology, Primer Cap Types, Cartridge Case Nomenclature, Types of Cartridge Case, Shotgun Ammunition, Bore Sizes, Pellet Sizes, Cartridge Loadings and Ballistics, Non Toxic Shot Types, Solid Slug Types, Military Colour Coding, Bullet Forms, Non Toxic Bullet Compositions.
Impulsivity
Authors: Patton Jim H. , Stanford Matthew S.
Published: September 2011

Impulsivity, with the possible exception of intelligence, is the personality dimension or trait that most broadly influences human endeavor. Impulsivity has been a topic of consideration throughout recorded history and discussed by classical philosophers. Over the past century, paper‐and‐pencil tests have been developed to test impulsivity and its three major dimensions, but these measures have still not been able to reliably predict how any one individual will react in any specific situation. Impulsivity relates directly to both impulsive and compulsive behavioral disorders, possibly mediated by some underlying central serotonergic dysfunction. Pharmacotherapy for these disorders has tended to focus on selective serotonin reuptake inhibitors (SSRIs) and antiepileptic drugs (AEDs). Psychotherapeutic interventions that have proved effective in the treatment of impulsivity and the impulse control disorders (both impulsive and compulsive) include cognitive behavioral therapy and dialectical behavioral therapy.
Firearms: Accidental Discharge
Authors: Heard Brian J.
Published: September 2011

A review of the major causes of a firearm ‘accidentally discharging’. This includes simple diagrams illustrating the various types of trigger mechanism, the average trigger pull weights for various weapons and some examples of weapons which were manufactured with the built in potential to accidentally discharge. The various scenarios are illustrated by a number of case examples which have been examined by the author.
Molecular Quantum Mechanics and Molecular Spectra, Molecular Symmetry, and Interaction of Matter with Radiation
Authors: Merkt Frédéric , Quack Martin
Published: September 2011

The basic experimental and theoretical concepts underlying molecular spectroscopy are presented. The equations and relations needed in practical applications of high‐resolution spectroscopy are provided. Group theoretical tools and their use in high‐resolution spectroscopy are introduced and illustrated by simple examples. Time‐dependent processes and quantum dynamics are presented and discussed in relation to spectroscopic observations. Coherent and incoherent radiative excitation and radiationless transitions are treated in relation to applications in molecular spectroscopy.
Conventions, Symbols, Quantities, Units and Constants for High‐Resolution Molecular Spectroscopy
Authors: Stohner Jürgen , Quack Martin
Published: September 2011

A summary of conventions, symbols, quantities, units, and constants which are important for high‐resolution molecular spectroscopy is provided. In particular, great care is taken to provide definitions which are consistent with the recommendations of the IUPAC “Green Book”, from which large parts of this article are drawn. While the recommendations in general refer to the SI (Système International), the relation to other systems and recommendations, which are frequently used in spectroscopy, for instance atomic units, is also provided. A brief discussion of quantity calculus is provided as well as an up‐to‐date set of fundamental constants and conversion factors together with a discussion of conventions used in reporting uncertainty of experimentally derived quantities. The article thus should provide an ideal compendium of many quantities of practical importance in high‐resolution spectroscopy.
AbInitio Theory for Accurate Spectroscopic Constants and Molecular Properties
Authors: Tew David P. , Klopper Wim , Bachorz Rafał A. , Hättig Christof
Published: September 2011

Having access to highly accurate potential energy surfaces (PESs) is a prerequisite for the ab initio calculation of accurate spectroscopic constants and molecular properties. The construction of such surfaces, however, is a formidable task. It not only requires solving of the time‐independent, nonrelativistic, clamped‐nuclei, electronic Schrödinger equation of the molecularn‐electron system at the highest possible level of approximation, but it also requires inclusion of small energy terms that are often neglected at other occasions. Such terms are, for example, due to nonadiabatic and relativistic effects (scalar and nonscalar). Nevertheless, the largest sources of error in calculating PESs are most often due to the inadequate description of the nonrelativistic electronic wave function of the molecularn‐electron system in the Born–Oppenheimer approximation. This article is concerned with these sources of error, which are related to the truncation of the one‐electron basis set of atomic functions and to the incomplete expansion of the wave function in a basis ofn‐electron functions. In particular, these errors diminish only extremely slowly with the extension of the one‐electron basis set when the wave function is expanded in terms ofn‐electron functions that are (antisymmetrized) products of one‐electron functions (orbitals). Coupled‐cluster theory in conjunction with explicitly correlated two‐electron geminals (instead of the more commonly used products of two orbitals) appears to be a promising approach toward obtaining an adequate description of the clamped‐nuclei, nonrelativistic electronic wave function and, thus, for the calculation of highly accurate PESs, from which accurate spectroscopic constants and molecular properties may be obtained.
Spherical Top Theory and Molecular Spectra
Authors: Boudon Vincent , Champion Jean‐Paul , Gabard Tony , Loëte Michel , Rotger Maud , Wenger Christian
Published: September 2011

In this article, we present an overview of the present state of the art of the theory of high‐resolution spherical‐top spectra in the framework of the effective Hamiltonian approach. We describe the specific features of this class of molecules to explain the basic concepts of the theoretical methods used for the analysis (line positions and intensities) and the simulation of absorption (including pure rotation) and Raman spectra of such species. The non conventional formalism that we use is essentially based on irreducible tensor methods and is especially adapted to computational treatments and global analyses of complex interacting band systems. We give examples concerning mainly methane (CH
4
) and sulfur hexafluoride (SF
6
). The efficiency of these methods is not restricted to spherical tops, as they also apply to other molecular species or spectroscopic problems. We demonstrate this through recent developments including the modeling of the effects of collisions on line shapes, the modeling of rovibronic effects, as well as extensions to molecules with lower symmetry. The computer implementation of the methods is an integral part of the modeling. We conclude the article with an overview of the free access programs and databases developed in the Dijon group for spherical‐top molecules and some other species.
Elements of Quantum Defect Theory
Authors: Jungen Ch.
Published: September 2011

Quantum defect theory (QDT) is concerned with the interaction of a single particle with an (atomic or molecular) target, which may be in an ionized or a neutral state. The formalism provides a unified theory of bound state spectroscopy, resonance phenomena, as well as elastic and inelastic scattering processes. In its most common formulation, quantum defect theory refers to Coulomb systems, particularly an electron moving in the field of a positively charged ion, and hence it is a theoretical tool for the description of atomic or molecular
Rydberg states.
The present article emphasizes the foundations of the theory, but a number of applications are also considered.
THz
and Submillimeter‐wave Spectroscopy of Molecular Complexes
Authors: Tanaka Keiichi , Harada Kensuke , Yamada Koichi M.T.
Published: September 2011

This article reviews the recent progress of terahertz (THz) and submillimter‐wave (SMMW) spectroscopy in the frequency range of 10–300 cm
−1
and its application to the study of weakly bound molecular complexes.

The first section describes the light sources used for generating THz radiation, which includes the backward‐wave oscillators (BWO), the multipliers with the GaAs monolithic membrane diode (MOMED), and the supperlattice electronic devices (SLED), as well as the tunable far infrared (TuFIR) lasers.

In the following section, we introduce extremely sensitive spectrometers developed for observing very weakly bound molecular complexes, such as the intra‐cavity OROTRON spectrometer and the millimeterwave‐Fourier transform microwave (MMW‐FTMW) double resonance spectrometer. We also review the traditional millimeter‐wave spectrometers, electric‐resonance optothermal spectrometers (EROS), and the tunable far‐infrared (TuFIR) laser spectrometers, which have also been applied successfully to study weakly bound molecular complexes.

In the last section, the recent topics of the THz and millimeterwave spectroscopy of molecular complexes are reviewed in the four subsections; (i) Rare gas‐molecule complexes: Rg‐HX, Rg‐CO, and Rg‐HCN, (ii) dimers: (CO)
2
, CO‐N
2
, HCN‐H
2
, and (H
2
O)
2
, (iii) water complexes (H
2
O)

n

, with
n
up to 6, and (iv) ion and radical complexes: ArSH, ArH
2
O, H
2
OHO
2
, and ArH
3
+
.
Fourier Transform Microwave Spectroscopy Measurement and Instrumentation
Authors: Grabow Jens‐Uwe
Published: September 2011

Microwavemolecular spectroscopy is progressing impressively. In part, profiting from recent experimental developments that combine jet‐expansion sources with elaborate means for preparation of new chemical systems, advances in spectroscopic instrumentation — namely, the rise of very sensitive and high‐resolution time‐domain techniques — are even more significant. Precise structural studies have always been a strength of rotational spectroscopy; now problems arising from convoluted intramolecular dynamics, such as conformational, tautomeric equilibria, and other large amplitude motions, as well as intermolecular vibrational energy redistribution and isomerization, can be targeted with the unrivaled precision of rotational investigations. Numerous interesting chemical systems like molecules with multiple concurrent internal motions, larger complexes, aggregates, biomolecules, and transient species were characterized recently — positioning microwave spectroscopy today as a prime method for the investigation of multidimensional flexible systems. Rotational studies elucidate an extensive range of intermolecular interactions, ranging from hydrogen bonding and van der Waals interaction to the unusual effects observed in quantum solvation. The development of microwave pulsed excitation multiresonance techniques and the advent of instantaneous broadband‐coverage microwave spectroscopy are impressively boosting the capabilities of rotational spectroscopy to quite routinely disentangle the unique spectral signatures that encode the structure and dynamics of hitherto pathological molecular cases. The versatile capabilities of microwave coherence spectroscopy are outlined in the treatment of time‐dependent interaction of rotating molecules with radiation.
Millimeter and Submillimeter Wave Spectroscopy and Astrophysical Applications
Authors: Ziurys Lucy M.
Published: September 2011

Millimeter and submillimeter spectroscopy has played a crucial role in the discovery and study of interstellar molecules by radio astronomy, as well as in the characterization of the rotational energy levels for numerous chemical compounds. A broad range of spectrometer designs have been developed for this basic direct absorption technique. Certain systems employ “free space” cells and Gaussian beam optics, while others incorporate mirrors in multipass configurations. Fast scanning methods have additionally been implemented. Synthetic techniques are also important in the astrophysical application of millimeter/submillimeter spectroscopy, as many potential interstellar species are free radicals and molecular ions. Many instruments employ glow discharges, ovens, and other exotic gas‐phase methods for the creation of transient molecules. Radical spectra usually exhibit a range of fine structure and hyperfine interactions which can complicate their analysis. Another challenge for millimeter/submillimeter spectroscopy is the study of simple organic molecules with functional groups that undergo hindered rotation. Millimeter and submillimeter spectroscopic measurements continue to provide the necessary rotational “rest frequencies” for molecule identification in space. Recent work has led to the interstellar discoveries of long‐chain carbon anions C4H−and C6H−, more complex organic molecules including CH3CONH2, and unusual refractory species such as CCP and AlO.
High‐Resolution Fourier Transform Infrared Spectroscopy
Authors: Albert Sieghard , Albert Karen Keppler , Quack Martin
Published: September 2011

Recent developments and applications of high‐resolution Fourier transform spectroscopy are reviewed. A short historical summary of the development of high‐resolution interferometric Fourier transform infrared (FTIR) spectrometers is given and the possibilities of the currently most highly resolving FTIR spectrometers, including a current prototype built for the Zürich group at the Swiss Light Source SLS as a synchrotron light source, are discussed. A short description of the principles of FTIR spectroscopy is given and the resolution of current spectrometers is illustrated by FTIR spectra of CO, CO2OCS, N2O, CS2, and CH4and its isotopomers. The computational tools necessary to analyze FTIR spectra are described briefly. As examples of rovibrational analysis of more complex spectra, selected molecules CHCl2F, CDBrClF, pyridine (C6H5N) and pyrimidine (C4H4N2), and naphthalene (C10H8) are discussed. The spectrum of CHCl2F, a fluorochlorocarbon, is of interest for a better understanding of the chemistry of the Earth's atmosphere. It also possesses an isotopically chiral isotopomer CH35Cl37ClF analyzed in natural abundance. CDBrClF is a chiral molecule and therefore the analysis of its rovibrational spectra provides the basis for carrying out further experiments toward the detection of molecular parity violation. The analyses of the pyridine, pyrimidine, and naphthalene FTIR spectra illustrate the potential of the new generation of FTIR spectrometers in the study of spectra and rovibrational dynamics of aromatic systems and molecules of potential biological interest. In particular, naphthalene is a prototype molecule useful in gaining an understanding of the unidentified infrared bands (UIBs) detected in several interstellar objects.
High‐resolution Infrared Laser Spectroscopy and Gas Sensing Applications
Authors: Sigrist Markus W.
Published: September 2011

The acceptance and the success of laser‐based trace gas sensing techniques crucially depend on the availability and performance of tunable laser sources combined with appropriate detection schemes. Near‐ and midinfrared sources (preferentially semiconductor and solid state lasers) are used today in various configurations with sensitive absorption detection methods (multipass, photoacoustic, and cavity ringdown arrangements). This article starts with a discussion of the approaches pursued to fulfill key requirements for gas sensors. In the main part, we present the challenges, performance, potential, and also limitations of laser‐based sensors in various applications. The examples cover ambient air monitoring, industrial sensing, isotope ratio determination, breath analysis in medical diagnosis, and finally analysis of urine samples for doping tests. Besides multicomponent capability, impressive sensitivities down to the parts per trillion level (1 in 1012), high specificity which enables differentiation between diastereoisomers (e.g., between ephedrine and pseudoephedrine, even in urine samples) or between isotopes (14N15N16O and15 N14 N16O, site selectivity), are dealt with. We describe both ground‐based and airborne instruments for time‐resolved measurements. Promising developments are expected to foster further progress of laser‐based sensors and stimulate their application in new areas.
High‐resolutionRaman Spectroscopy of Gases
Authors: Weber Alfons
Published: September 2011

A review of high‐resolution Raman spectroscopy of gases, including spontaneous, incoherent Raman spectroscopy, as well as of nonlinear techniques for coherent anti‐Stokes scattering (CARS), stimulated Raman gain (SRG) and stimulated Raman loss (SRL) spectroscopy, and photoacoustic Raman spectroscopy (PARS) in the frequency domain is presented. Femtosecond degenerate four‐wave mixing spectroscopy (Fs‐DFWM) and Raman‐induced polarization spectroscopy (RIPS) in the time domain are discussed. Also treated are the broadenings of Raman lines due to the Doppler and pressure effects. Basic theoretical notions and working equations for the analysis of highly resolved spectra are presented. Examples are drawn from the literature to illustrate the respective advantages and disadvantages of the various techniques. The interplay between high‐resolution Raman spectroscopy, infrared spectroscopy, and ab initio computational schemes is illustrated. The article concludes with an overall assessment of the respective advantages and disadvantages of the methods used in high‐resolution Raman spectroscopy.
Mass and Isotope‐Selective Infrared Spectroscopy
Authors: Hippler Michael , Miloglyadov Eduard , Quack Martin , Seyfang Georg
Published: September 2011

Recent advances in laser spectroscopic techniques make it possible to obtain mass‐ and isotope‐selective infrared spectra of gas‐phase species at high resolution and reduced hot‐band spectral congestion. In these techniques, infrared excitation is coupled with ultraviolet multiphoton ionization and detection of the resulting ions in a mass spectrometer, which allows the separation of contributions of different isotopomers and, more generally, species of different mass in a mixture. In combination with jet cooling techniques, spectra are obtained for very cold molecules. These spectra can then be analyzed to extract information on dynamical processes such as intramolecular vibrational redistribution or tunneling and rearrangement processes, and on how intramolecular dynamics is influenced by vibrational excitation and isotope effects. In this review, we introduce isotope‐selective infrared spectroscopic techniques and present some selected applications on isotope effects and intramolecular dynamics of vibrationally excited chloroform, aniline, and benzene obtained by isotope‐selective infrared spectroscopy.
Electronic Spectroscopy of Transient Molecules
Authors: Guennoun Zohra , Maier John P.
Published: September 2011

The generation and characterization of transient species is a challenge for experimentalists as these species are short‐lived and reactive. Our group has focused on the measurement of the electronic spectra of unstable molecules relevant to astrophysical observations as well as to terrestrial environments. Methods of generating and collecting the electronic spectra of radicals and ions have been developed. By first using a mass‐selected matrix isolation technique, the transitions of these species are obtained in neon matrices, following which the gas‐phase transitions can be sought. To this end, an assortment of techniques is employed, for example, cavity ring‐down and frequency modulation absorption spectroscopy, degenerate four‐wave mixing, resonant multiphoton ionization, and photofragmentation schemes that utilize the cooling capabilities of an ion trap.

These gas‐phase‐based approaches are illustrated by the electronic spectra of a number of key species providing detailed information about their electronic structure, thus allowing for direct comparison between astronomical observations and theory. The studies of the carbon chains have led to interesting astrophysical implications for the systems, which could be responsible for the diffuse interstellar bands.
High‐resolution RotationalRaman Coherence Spectroscopy with Femtosecond Pulses
Authors: Frey Hans‐Martin , Kummli Dominique , Lobsiger Simon , Leutwyler Samuel
Published: September 2011

Femtosecond time‐resolved rotational coherence spectroscopy (RCS), when applied in a Raman scattering version, can be utilized for the measurement of highly accurate rotational and centrifugal constants of ground and vibrationally excited states of nonpolar molecules. A brief outline of the theoretical background is given, including the basics of rotational coherence spectroscopy, nonlinear optical four‐wave mixing (FWM), molecular polarizability, the rotational Raman process, nuclear spin statistics, and collisional dephasing. An experimental setup for femtosecond rotational Raman RCS measurements is described, featuring some of the points necessary to achieve high experimental accuracy. Rotational Raman RCS spectroscopy has been performed on a number of nonpolar linear and symmetric‐top molecules. The examples presented here (CS2, cyclobutane, and cyclooctatetraene) are selected to show the scope of the method and currently achievable accuracy of the rotational and the centrifugal distortion constants, as well as the detailed considerations necessary to achieve these results. The last section reviews a procedure for the determination of semiexperimental equilibrium structures.
Theory of the Jahn–Teller Effect
Authors: Köppel Horst , Cederbaum Lorenz S. , Mahapatra Susanta
Published: September 2011

An overview of theoretical treatments of Jahn–Teller (JT) and pseudo‐Jahn–Teller (PJT) coupling effects involving doubly degenerate electronic states is presented. It is divided into a general part, focusing on the pertinent Hamiltonians and the properties of the adiabatic potential energy surfaces, and the presentation of specific examples, where the consequences for molecular electronic spectra are demonstrated. Besides isolatedEelectronic states with various types and symmetries of the JT‐active modes, interactions between degenerate and nondegenerate as well as between different degenerate states are also covered. The examples are dominated by strong nonadiabatic coupling effects that are caused by the various conical intersections appearing in these systems. The similar nature of JT and PJT intersections in this respect is pointed out.
Effective Hamiltonians for Electronic Fine Structure and Polyatomic Vibrations
Authors: Field Robert W. , Baraban Joshua H. , Lipoff Samuel H. , Beck Annelise R.
Published: September 2011

The effective Hamiltonian,Heff, is an important tool for analyzing and representing the spectra, energy levels, and dynamics of atoms and molecules. By replacing the rigorous but intractable exact Hamiltonian,Hexact, with a model that is designed to share most of its essential qualitative and quantitative characteristics, the spectroscopist can derive valuable insights from raw, incomplete, and partially assigned spectra. These insights guide the optimal design of information‐rich new experiments and computations and can reveal the dynamical mechanisms encoded in the spectra. Here we describe the theory, construction, and limitations of effective Hamiltonians, drawing examples primarily from the electronic fine structure of diatomic molecules and the vibrational structure of polyatomic molecules. Current ideas for extending the accuracy, flexibility, and mechanistic transparency of effective Hamiltonian models to future areas of research, especially at extremely high excitation energies, are discussed. Unconventional applications of traditional effective Hamiltonians are illustrated by example, especially schemes to visualize and classify large‐amplitude motions. Quantum and classical mechanicalHeffmodels derived from frequency‐domain spectra are the best possible sources for insights into time‐domain phenomena. In particular, the existence of large‐amplitude regular eigenstates embedded in a principally ergodic bath is uniquely relevant to schemes for external control of intramolecular dynamics and the validity of ergodicity‐based predictions of the rates of unimolecular processes.
Helium Droplets as Nanocryostats for Molecular Spectroscopy—from the Vacuum Ultraviolet to the Microwave Regime
Authors: Callegari Carlo , Ernst Wolfgang E.
Published: September 2011

The spectroscopy of pure and doped helium nanodroplets is reviewed, with the goal to provide a reference for nonspecialists. The technical aspects of a helium‐droplet machine for spectroscopy are addressed first. Spectroscopic methods and results are then presented, loosely divided according to the degree of freedom being excited (that is, practically, by photon energy). Technical aspects pertaining to each branch are presented, along with an overview of the physics that can be studied and of possible physical‐chemistry applications. References for further reading are provided.
Molecular Clusters and Noncovalent Bonds Probed by Photoionization and Photoelectron Spectroscopy
Authors: Müller‐Dethlefs Klaus , Riese Mikko
Published: September 2011

This article gives a brief impression of how high‐resolution photoion and photoelectron spectroscopy can be applied to investigate molecular clusters. A short theoretical description of the nature of noncovalent interactions is given. In this context, we discuss which properties can best be investigated by applying a variety of spectroscopic techniques. The principles of the main photoion/photoelectron spectroscopy techniques are explained and examples of investigations of molecular clusters are presented. Van der Waals (vdW) clusters that are composed of a molecule and one or more rare‐gas atoms as well as hydrogen‐bonded hetero dimers are discussed. Complexes containing aniline or phenol are interesting because of two principal ligand binding sites, thus allowing either hydrogen bonding via the NH2or OH group (H‐bound) and vdW bonding via interaction with the aromatic π system (π‐bound). For phenol…Arnand aniline…Arn(n = 1, 2), we discuss the very recently observed phenomenon of π→ H isomerization in the cation cluster. The interplay between different types of intermolecular bonds during fragmentation is discussed for the example of phenol…water…argon. For the fluorobenzene…Ar cluster, we demonstrate how structural information from rotational constants for the ionic state can be obtained from partially rotational‐resolved zero‐electron kinetic energy (ZEKE) spectra.
Spectroscopy and Reaction Dynamics of Anions
Authors: Wester Roland
Published: September 2011

This article covers the status and the recent advances in experimental studies on the spectroscopy and the dynamics of negative ions. Bound–bound absorption spectroscopy in the different frequency ranges as well as bound‐free photodetachment and photoelectron spectroscopy of anions are discussed. Furthermore, recent developments in the field of reaction kinetics and dynamics of negative ions are presented.
High‐resolution Photoelectron Spectroscopy
Authors: Merkt Frédéric , Willitsch Stefan , Hollenstein Urs
Published: September 2011

The evolution of photoelectron spectroscopy of neutral molecules in the gas phase, from its first applications in the early 1960s to the present day, is reviewed with emphasis on the description of methods that have contributed to the improvement of resolution. In the early days, photoelectron spectroscopy was very successfully used to study the electronic structure of molecules. As the resolution improved, the emphasis gradually shifted to studies of the structure and dynamics of molecular cations. Current methods enable one to fully resolve the rotational structure in the photoelectron spectra of polyatomic molecules and even to measure the fine and hyperfine structures of positively charged atoms and small molecules. Several of the methods providing high resolution make use of the long lifetimes and electric‐field‐ionization properties of high Rydberg states and give access to detailed information on molecular ionization channels and molecular photoionization.
Precision Laser Spectroscopy in the Extreme Ultraviolet
Authors: Eikema Kjeld S.E. , Ubachs Wim
Published: September 2011

Techniques for the production of short wavelengths in the extreme ultraviolet wavelength range are described, spanning low‐order harmonic generation in the perturbative regime for narrow bandwidth XUV production to the plateau‐regime with the three‐step collisional model for the generation of high harmonics with broadband ultrafast pulses. In addition, the intermediate regime is discussed for pulses of 300 ps duration, as well as the regime of harmonic conversion based on continuous wave lasers aiming at the production of coherent Lyman‐α radiation. Applications of XUV sources in the frequency domain typically rely on the production of XUV‐light from narrowband Fourier‐transform‐limited pulses for recording high‐resolution spectra. Alternatively, harmonically upconverted pulses of ultrashort duration (with inter‐pulse coherence) can be used for spectroscopic studies in the time and frequency domain (such as direct frequency comb spectroscopy techniques). Examples of both approaches for atomic and molecular spectroscopy are discussed at some length. For precision metrology on atomic systems, a focus is put on the Lamb shift determination in the He ground state. In the realm of molecular spectroscopy, predissociation phenomena in the nitrogen molecule are highlighted, with relevance for dissociation processes occurring in the upper layers of the Earth atmosphere. Similar predissociation phenomena in carbon monoxide are also treated in some detail, in this case with relevance for the chemistry in interstellar clouds. Precision XUV spectroscopy of molecular hydrogen is discussed as well, as it relates to the possibility of detecting a variation of the proton–electron mass ratio on a cosmological time scale. In the last section, applications of direct frequency comb spectroscopic techniques at short wavelengths are explained and prospects are given for using these techniques at extreme ultraviolet wavelengths.
Femtosecond and Attosecond Light Sources and Techniques for Spectroscopy
Authors: Gallmann Lukas , Keller Ursula
Published: September 2011

The quest for high‐resolution time‐resolved studies of ultrafast physical and chemical processes is an important driver behind ultrafast laser technology. The large variety of physical and chemical systems leads to the need of ultrashort laser pulses at many different wavelengths. In this article, we review the most important femtosecond and attosecond light sources available from the infrared to the X‐ray spectral region and give an introduction to the underlying physics and technology. We discuss techniques for ultrashort pulse diagnostics, which can be considered as prototypes for time‐resolved experiments in the femtosecond and attosecond domain. The topics covered in this article are intended as a starting ground and the interested reader is provided with references for further exploration.
Photodissociation Dynamics of Polyatomic Molecules: Diffuse Structures and Nonadiabatic Coupling
Authors: Schinke Reinhard
Published: September 2011

The photodissociation of polyatomic molecules is discussed in terms of accurate potential energy surfaces for excited electronic states and exact quantum mechanical dynamics calculations. After a brief presentation of the theoretical tools, diffuse vibrational structures are discussed in detail for several triatomic molecules in order to elucidate the relationship with the intramolecular dynamics in excited states. Another focus is the various types of nonadiabatic transitions between different states along the dissociation path.
Multiphoton Resonance Spectroscopy of Biological Molecules
Authors: Häber Thomas , Kleinermanns Karl
Published: September 2011

High‐resolution gas‐phase spectroscopy of biomolecules allows us to distinguish between the intrinsic properties of biomolecules and those properties that are induced by solvation or by the geometrical restrictions of the environment. In the gas phase, we can study the isolated biomolecules and their water clusters under size‐controlled conditions. Comparison with experiments in solution then provides information about the specific role of the biological environment, like solvent effects or geometric constraints of nucleic acids and peptides. However, gas‐phase studies are often complicated by the thermal instability of many biomolecules, which often prevents the use of conventional thermal sources for vaporizing them. This obstacle has been overcome by applying laser desorption techniques to biomolecules as a gentle alternative to thermal heating in combination with very sensitive detection schemes like resonance‐enhanced multiphoton ionization, double resonance methods, and dispersed fluorescence.
Spectroscopy of the Earth's Atmosphere
Authors: Flaud Jean‐Marie , Orphal Johannes
Published: September 2011

In this article we describe the applications of molecular spectroscopy for the study of the Earth's atmosphere. After a short historical introduction, we present the principal physical and chemical properties of the atmosphere and discuss current fields of research (i.e., the evolution of the ozone layer, tropospheric air pollution, and increasing greenhouse gas concentrations). We then briefly describe the basic theory of atmospheric radiative transfer and the most important spectroscopic databases. After a presentation of the different experimental techniques that are used to measure atmospheric spectra, some examples of recent studies (linking laboratory work, theoretical studies, and atmospheric remote‐sensing experiments) are given to illustrate current topics of research in this field.
Bioinspired Tunable Lens with Muscle‐Like Electroactive Elastomers
Authors: Carpi Federico , Frediani Gabriele , Turco Simona , De Rossi Danilo
Published: September 2011

Optical lenses with tunable focus are needed in several fields of application, such as consumer electronics, medical diagnostics and optical communications. To address this need, lenses made of smart materials able to respond to mechanical, magnetic, optical, thermal, chemical, electrical or electrochemical stimuli are intensively studied. Here, we report on an electrically tunable lens made of dielectric elastomers, an emerging class of “artificial muscle” materials for actuation. The optical device is inspired by the architecture of the crystalline lens and ciliary muscle of the human eye. It consists of a fluid‐filled elastomeric lens integrated with an annular elastomeric actuator working as an artificial muscle. Upon electrical activation, the artificial muscle deforms the lens, so that a relative variation of focal length comparable to that of the human lens is demonstrated. The device combined optical performance with compact size, low weight, fast and silent operation, shock tolerance, no overheating, low power consumption, and possibility of implementation with inexpensive off‐the‐shelf elastomers. Results show that combing bioinspired design with the unique properties of dielectric elastomers as artificial muscle transducers has the potential to open new perspectives on tunable optics.
Using biological markets principles to examine patterns of grooming exchange in Macaca thibetana
Authors: Balasubramaniam K.N. , Berman C.M. , Ogawa H. , Li J.
Published: September 2011

Biological markets principles offer testable hypotheses to explain variation in grooming exchange patterns among nonhuman primates. They predict that when within‐group contest competition (WGC) is high and dominance hierarchies steep, grooming interchange with other “commodity” behaviors (such as agonistic support) should prevail. In contrast, when WGC is low and gradients shallow, market theory predicts that grooming reciprocity should prevail. We tested these predictions in a wild, provisioned Tibetan macaque (Macaca thibetana) group across six time periods during which the group had been subjected to varying degrees of range restriction. Data on female–female aggression, grooming, and support were collected using all‐occurrences and focal animal sampling techniques, and analyzed using ANCOVA methods and correlation analyses. We found that hierarchical steepness varied significantly across periods, but did not correlate with two indirect indicators of WGC (group size and range restriction) in predicted directions. Contrary to expectations, we found a negative correlation between steepness and group size, perhaps because the responses of group members to external risks (i.e. prolonged and unavoidable exposure to humans) may have overshadowed the effects of WGC. As predicted, grooming reciprocity was significant in each period and negatively correlated with steepness, even after we controlled group size, kinship, rank differences, and proximity. In contrast, there was no evidence for grooming interchange with agonistic support or for a positive relationship between interchange and steepness. We hypothesize that stressful conditions and/or the presence of stable hierarchies during each period may have led to a greater market demand for grooming than support. We suggest that future studies testing these predictions consider more direct measures of WGC and commodities in addition to support, such as feeding tolerance and access to infants. Am. J. Primatol. 73:1269–1279, 2011. © 2011 Wiley Periodicals, Inc.
Prevalence of magnetic resonance imaging–defined atrophic and hypertrophic phenotypes of knee osteoarthritis in a population‐based cohort
Authors: Roemer Frank W. , Guermazi Ali , Niu Jingbo , Zhang Yuqing , Mohr Andreas , Felson David T.
Published: September 2011

Objective

To describe the association of osteophytes with concomitant cartilage damage, assessed using semiquantitative magnetic resonance imaging (MRI), and to describe the prevalence of atrophic and hypertrophic phenotypes of tibiofemoral knee osteoarthritis (OA) in a population‐based cohort.

Methods

Participants of the Framingham Knee Osteoarthritis Study were examined with a 1.5T MRI system using triplanar intermediate‐weighted fat‐suppressed sequences. Cartilage and osteophytes were assessed using the Whole‐Organ Magnetic Resonance Imaging Score (WORMS). Overall prevalence of knees with severe cartilage damage and concomitant osteophyte status were described. Odds ratios for the likelihood of having severe cartilage damage according to osteophyte size were estimated using a logistic regression model. An additional analysis assessed knees according to phenotype in relation to radiographic OA status, with the atrophic phenotype being defined as knees with absent or only tiny osteophytes (WORMS grade ≤2 on a 0–7 scale) in all 10 tibiofemoral subregions but exhibiting severe cartilage damage, and the hypertrophic phenotype being defined as knees with large osteophytes (WORMS grade ≥5 on a 0–7 scale) but lacking substantial cartilage damage.

Results

In this study, 1,597 knees of 1,248 subjects were included. Of the 67 knees with large osteophytes, 54 (80.6%) exhibited severe cartilage damage. The risk of severe cartilage damage increased markedly with increasing osteophyte size. Twenty‐one knees (1.3%) showed an atrophic phenotype. Only 3 knees (0.2%) exhibited a hypertrophic phenotype.

Conclusion

The majority of knees with severe tibiofemoral cartilage damage exhibited moderate to large osteophytes. The larger the osteophyte, the more likely was the presence of severe cartilage damage. A minority of knees exhibited the atrophic phenotype, which also included knees without radiographic OA. The hypertrophic phenotype was extremely rare.
The clinical picture of rheumatoid arthritis according to the 2010 American College of Rheumatology/European League Against Rheumatism criteria: Is this still the same disease?
Authors: de Hair M. J. H. , Lehmann K. A. , van de Sande M. G. H. , Maijer K. I. , Gerlag D. M. , Tak P. P.
Published: September 2011

Objective

To examine the implications of using the new classification criteria for rheumatoid arthritis (RA) in clinical practice in a cohort of patients with very early arthritis.

Methods

The study group comprised 301 disease‐modifying antirheumatic drug–naive patients with early arthritis. The baseline diagnosis was assessed by applying the 1987 American College of Rheumatology (ACR) and 2010 ACR/European League Against Rheumatism (EULAR) criteria for RA as well as established diagnostic criteria for other rheumatic diseases. Diagnostic and prognostic data were collected after 2 years of followup. Fulfillment of the 2010 ACR/EULAR criteria was evaluated in the subset of patients in whom undifferentiated arthritis (UA) was diagnosed when the 1987 ACR criteria were applied, and fulfillment of RA criteria over time was tested by applying the 2 different criteria sets.

Results

The median arthritis duration at baseline was 4 months (range 0–12 months). At baseline, 28% of the patients fulfilled the 1987 ACR criteria, and 45% fulfilled the 2010 ACR/EULAR criteria for RA. Among the patients classified as having UA at baseline according to the 1987 ACR criteria, 36% had fulfilled the 2010 ACR/EULAR criteria already at baseline. Among the patients classified as having UA at baseline but who fulfilled the 1987 ACR criteria after 2 years of followup, 85% had fulfilled the 2010 ACR/EULAR criteria at baseline. Patients with early disease who fulfilled the 2010 ACR/EULAR criteria were less likely to be autoantibody positive and more likely to have monarthritis at presentation than those fulfilling the 1987 ACR criteria.

Conclusion

Use of the 2010 ACR/EULAR criteria clearly allows earlier diagnosis of RA, although the clinical picture is slightly different on the group level, and RA may be falsely diagnosed in some patients with self‐limiting disease.
Immature muscle precursors are a source of interferon‐β in myositis: Role of Toll‐like receptor 3 activation and contribution to HLA class I up‐regulation
Authors: Tournadre Anne , Lenief Vanina , Eljaafari Assia , Miossec Pierre
Published: September 2011

Objective

To investigate the production of type I interferon (IFN) by myoblasts and to identify its cell source and the link to Toll‐like receptor (TLR) and C‐type lectin receptor (CLR) expression and function in myositis biopsy sections.

Methods

Production of IFNβ was assessed in cultured myoblasts after stimulation with the TLR‐3 agonist poly(I‐C) or with cytokines involved in Th1 and Th17 differentiation. Expression of HLA class I molecules by myoblasts was analyzed by fluorescence‐activated cell sorting after activation of TLR‐3 and IFNβ neutralization. In muscle biopsy samples from patients with polymyositis or dermatomyositis, expression of IFNβ, CD56 (a marker of immature muscle precursors), and HLA class I was analyzed using immunohistochemistry. Inflammatory infiltrates were characterized for the expression of myeloid dendritic cells (DCs), their associated CLRs, and the products of activated DCs, interleukin‐12 (IL‐12), and IL‐23.

Results

In cultured myoblasts, stimulation of TLR‐3 induced the production of IFNβ when combined with IFNγ and up‐regulated the expression of HLA class I molecules, which was decreased after IFNβ blockade. In myositis biopsy tissues, immature muscle precursors overexpressing HLA class I were identified as a source of IFNβ. CLRs associated with myeloid DCs were broadly expressed in inflammatory infiltrates, in association with IL‐12 and IL‐23, and with immature muscle precursors.

Conclusion

Immature muscle precursors may represent a local source of IFNβ and the target of an immune response involving activated DCs associated with the expression of CLRs and of IL‐12 and IL‐23, which are implicated in T cell polarization. In turn, such local production of IFNβ after TLR‐3 activation in the presence of the Th1 cytokine IFNγ may explain HLA class I overexpression in myositis.
Noninvasive Imaging of Ethanol‐Induced Developmental Defects in Zebrafish Embryos Using Optical Coherence Tomography
Authors: Divakar Rao K. , Upadhyaya Piyush , Sharma Mrinalini , Gupta P. K.
Published: September 2011

In this article, we report the use of optical coherence tomography for noninvasive cross‐sectional real‐time imaging of ethanol‐induced developmental defects in zebrafish embryos larvae. For ethanol concentration of over 300 mM, developmental defects of eye (shrinkage and retinal abnormalities), malformation of the notochord and ataxia arising due to the toxic effects of ethanol were observed in OCT images from 3 days post fertilization onwards. The results suggest that OCT could be a valuable tool for noninvasive assessment of birth defects in small animal systems.
Sesquiterpenoids from the Endophytic Fungus Trichoderma sp. PR‐35 of Paeonia delavayi
Authors: Wu Shao‐Hua , Zhao Li‐Xing , Chen You‐Wei , Huang Rong , Miao Cui‐Ping , Wang Jiao
Published: September 2011

A new bisabolane‐type sesquiterpene, trichoderic acid (1), and a new acorane‐type sesquiterpene, 2β‐hydroxytrichoacorenol (2), along with three known compounds, cyclonerodiol (3), cyclonerodiol oxide (4), and sorbicillin (5), were isolated from the culture broth of Trichoderma sp. PR‐35, an endophytic fungus isolated from Paeonia delavayi. Their structures were elucidated on the basis of their IR, MS, and 1D‐ and 2D‐NMR analyses. The antibacterial and antifungal activities of 1–5 towards various types of bacteria and fungi were tested. Most of the compounds showed moderate or weak antimicrobial activities in an agar‐diffusion assay.
Lobophytones U – Z1, Biscembranoids from the Chinese Soft Coral Lobophytum pauciflorum
Authors: Yan Pengcheng , Deng Zhiwei , van Ofwegen Leen , Proksch Peter , Lin Wenhan
Published: September 2011

Chemical examination of a Chinese soft coral Lobophytum pauciflorum resulted in the isolation of seven new biscembranoids named lobophytones U–Z1 (1–7, resp.), together with methyl sartortuoate (8) and nyalolide (9). The structures of the new compounds were elucidated by 1D‐ and 2D‐NMR (COSY, HSQC, HMBC, and NOESY) spectroscopic analysis in association with MS and IR data. All compounds were tested against lipopolysaccharide (LPS)‐induced nitric oxide (NO) release in mouse peritoneal macrophage. Lobophytone Z (6) inhibited NO production with an IC50 value of 2.6 μM. Lobophytone H (1) showed inhibitory activities against the bacteria S. aureus and S. pneumoniae.
Conidiogenones H and I, Two New Diterpenes of Cyclopiane Class from a Marine‐Derived Endophytic Fungus Penicillium chrysogenum QEN‐24S
Authors: Gao Shu‐Shan , Li Xiao‐Ming , Zhang Yi , Li Chun‐Shun , Wang Bin‐Gui
Published: September 2011

Two new tetracyclic diterpenes of the rarely reported cyclopiane class, conidiogenones H and I (1 and 2, resp.), along with five related congeners, conidiogenones B – D and F (3–5 and 6, resp.) and conidiogenol (7), were characterized from the culture extracts of Penicillium chrysogenum QEN‐24S, an endophytic fungus derived from an unidentified marine red algal species of the genus Laurencia. The structures of these compounds were established on the basis of extensive spectroscopic analysis. The inhibitory activity of theses diterpenes against four bacteria and one pathogen fungus was evaluated. Conidiogenone B (3) showed potent activity against Methicillin resistant Staphylococcus aureus (MRSA), Pseudomonas fluorescens, P. aeruginosa, and Staphylococcus epidermidis (each with a MIC value of 8 μg/ml), while conidiogenol (7) showed obvious activity against P. fluorescens and S. epidermidis (each with a MIC value of 16 μg/ml). This is the first report on antimicrobial activity of cyclopiane diterpenes.