bluuebunny/crossref_metadata_2025_split huggingface dataset:
The hybrid disks: a search and study to better understand evolution of disks
Authors: Péricaud J. , Di Folco E. , Dutrey A. , Guilloteau S. , Piétu V. 
Published: December 2016

Context. The increased sensitivity of millimeter-wave facilities now makes possible the detection of low amounts of gas in debris disks. Some of the gas-rich debris disks harbor peculiar properties, with possible pristine gas and secondary generated dust. The origin of the gas in these hybrid disks is strongly debated and the current sample is too sparse to understand this phenomenon.
Aims. More detections are necessary to increase the statistics on this population. Lying at the final stages of evolution of proto-planetary disks and at the beginning of the debris disk phase, these objects could provide new insight into the processes involved in the making of planetary systems.
Methods. We carried out a deep survey of the CO J = 2 → 1 and CO J = 3 → 2 lines with the APEX and IRAM radiotelescopes in young debris disks selected according to hybrid disk properties. The survey is complemented with a bibliographic study of the ratio between the emission of the gas and the continuum (SCO/Fcont) in CTTS, Herbig Ae, WTTS, hybrid, and debris disks.
Results. Our sub-mm survey comprises 25 stars, including 17 new targets, and we increase the sensitivity limit by a factor 2 on eight sources compared to similar published studies. We report a 4σ tentative detection of a double-peaked CO J = 2 → 1 line around HD 23642; an eclipsing binary located in the Pleiades. We also reveal a correlation between the emission of the CO gas and the dust continuum from CTTS, Herbig Ae and few debris disks. The observed trend of the gas to dust flux ratio suggests a concurrent dissipation of the dust and gas components. Hybrid disks systematically lie above this trend, suggesting that these systems may witness a transient phase, when the dust has evolved more rapidly than the gas, with a flux ratio SCO/Fcont enhanced by a factor of between 10 and 100 compared to standard (proto-)planetary disks.
Extent of Endoscopic Resection for Anterior Skull Base Tumors: An MRI-Based Volumetric Analysis
Authors: Koszewski Ian , Avey Gregory , Ahmed Azam , Leonhard Lucas , Hoffman Matthew , McCulloch Timothy 
Published: December 2016

Objective To determine the volume of ventral skull base tumor removed following endoscopic endonasal (EEA) resection using MRI-based volumetric analysis and to evaluate the inter-rater reliability of such analysis.
Design Retrospective case series.
Setting Academic tertiary care hospital.
Participants EEA patients November 2012 to August 2015.
Main Outcome Measures Volumetric analysis of pre- and immediately postoperative MR imaging was performed independently by two investigators. The percentage of total tumor resected was evaluated according to resection goal and tumor type.
Results A total of 39 patients underwent resection. Intraclass correlation coefficients between the raters were 0.9988 for preoperative and 0.9819 for postoperative images. Tumors (and average percentage removed) included 17 nonsecreting pituitary adenomas (95.3%), 8 secreting pituitary adenomas (86.2%), 4 meningiomas (81.6%), 3 olfactory neuroblastomas (100%), 2 craniopharyngiomas (100%), 1 large B–cell lymphoma (90.5%), 1 germ cell neoplasm (48.3), 1 benign fibrous connective tissue mass (93.4%), 1 epidermoid cyst (68.4%), and 1 chordoma (100%). For tumors treated with intent for gross total resection, 96.9 ± 4.8% was removed.
Conclusion EEAs achieved tumor resection rates of ∼97% when total resection was attempted. The radiographic finding of residual tumor is of uncertain clinical significance. The volumetric analysis employed in this study demonstrated high inter-rater reliability and could facilitate further study.
Environmental Factors Associated with the Upstream Migration of Fall-Run Chinook Salmon in a Regulated River
Authors: Peterson Matthew L. , Fuller Andrea N. , Demko Doug 
Published: December 2016

Abstract
We examined upstream migration patterns of adult Chinook Salmon Oncorhynchus tshawytscha in relation to environmental factors and two management actions (installation of a rock barrier at a distributary and managed pulse flows). Data was collected using a portable resistance board weir and a Vaki Riverwatcher system that provided accurate daily counts of fall-run Chinook Salmon on their spawning migration. Akaike's information criterion and multimodel inferential approaches, as well as generalized additive models, were used to assess the relative influence of water temperature, flow, moon illumination, weather, operation of a rock barrier, and managed pulse flows to explain the magnitude of daily counts and proportions of Chinook Salmon observed at the weir. Over the 12-year study period (2003–2014), we observed 38,206 Chinook Salmon. The installation of a rock barrier in the lower reaches of the San Joaquin River had positive and consistent influences on daily counts in the years it was installed. Although managed pulse flows to stimulate upstream migration have been used since the early 1990s, our analyses found managed pulse flows only appeared in the top generalized linear models in 2 of the 11 complete years of data analyzed. Managed pulse flows resulted in immediate increases in daily passages, but the response was brief and represented a small portion of the total run. A strong nonlinear response between migratory activity and discharge levels was observed for Chinook Salmon, indicating no additional increase in daily counts when pulse flows exceeded 20 m3/s. Current management requirements in the Stanislaus River exceed this level and adjustment should be considered based on the findings of this study, particularly given the need to balance beneficial uses of a limited water supply. This study provides a scientific approach to determine biologically relevant flow prescriptions for upstream migration of fish in regulated streams.
Received February 5, 2016; accepted September 15, 2016Published online December 21, 2016
Introduction
Authors: Johnson Steven D. , Schiestl Florian P. 
Published: December 2016

AbstractThis chapter focuses on the historical development of ideas about mimicry, including the discovery of floral mimicry, and provides an overview of the key concepts in mimicry research. It defines terms used in mimicry as used throughout the book. The mimicry concepts described include adaptive resemblance, cognitive misclassification of mimics by operators, the differences between convergent and advergent evolution, and the roles of honest signals and reliable cues in model organisms. This chapter also clarifies concepts relating to imperfect and accurate mimicry, as well as frequency dependence. The applicability of the concepts of Batesian and Müllerian mimicry to pollination systems is discussed.
The evolution and maintenance of floral rewardlessness
Authors: Johnson Steven D. , Schiestl Florian P. 
Published: December 2016

AbstractThis chapter examines the evolutionary factors behind the losses and gains of floral rewards. While mimicry is associated with plant lineages that lack floral rewards, rewardlessness and mimicry are not synonymous. Pollination typically takes the form of a biological transaction, whereby plants offer a material reward in exchange for a sexual service facilitated by animals. This is considered as a mutualism because both partners benefit but in reality these systems involve intense mutual exploitation—either partner will readily “cheat” if provided with the opportunity to do so. Not all deceptive plant species rely on mimicry (some rely solely on generalized attractive signals), but there is certainly a strong association between floral rewardlessness and various forms of mimicry. A key question is whether rewardlessness generally evolved before, together with, or after the evolution of mimicry in plant lineages, and this issue is explored in this chapter.
Batesian food-source mimicry
Authors: Johnson Steven D. , Schiestl Florian P. 
Published: December 2016

AbstractPlants that lack floral rewards can attract pollinators if their flowers sufficiently resemble those of sympatric food-rewarding plants. This is because animals that associate the signals of rewarding flowers with food may also be attracted by similar signals in a deceptive species. The success of this form of Batesian mimicry depends on how easily pollinators can be duped in the first place and on their subsequent ability to learn to avoid the deceptive flowers. Food-source mimicry in non-rewarding flowers has close parallels with Batesian protective mimicry in terms of frequency dependence and the evolution of geographic polymorphisms. Some aspects of food source mimicry are controversial and the chapter is organized around the different lines of evidence for this form of mimicry in plants.
The Physics of Solids
Authors: Ketterson J. B. 
Published: December 2016

Abstract
This text covers the basic physics of the solid state starting at an elementary level and advancing, in stages. In addition to treating the fundamental elastic, electrical, thermal, magnetic, structural, electronic, transport, optical, mechanical, and compositional properties, the text also discusses topics like superfluidity and superconductivity, along with special topics such as strongly correlated systems, high temperature superconductors, the quantum Hall effects, and graphene. Particular emphasis is given to so-called first principles calculations utilizing modern density functional theory, which for many systems now allow accurate calculations of the electronic, magnetic, and thermal properties.
The Parameterization of Band Structures: Applications to Semiconductors
Authors: Ketterson J. B. 
Published: December 2016

Abstract
The time involved to calculate many k-points can be excessive even if an accurate band structure is available. Therefore it is convenient to have some sort of scheme to fit the energy bands with some reasonably small set of parameters. Here we can envision “interpolating” between energy eigenvalues obtained from a band structure calculation, or possibly fitting experimental data, e.g., that from photo-emission experiments. For materials with complicated constant energy surfaces, the best fitting schemes are those based on a band structure formalism, e.g., the pseudopotential or the tight binding methods. This chapter discusses the following techniques: the k⋅p method for diamond-like materials at the zone centre; inverted band structures; and the Slater–Koster method for diamond-like structures. The chapter ends with some problems for the reader.
Measuring the Electronic Energy Spectrum On and Off the Fermi Surface
Authors: Ketterson J. B. 
Published: December 2016

Abstract
This chapter discusses various methods that have been used to measure the energy spectrum of electrons in both metals and insulators. For metals a property of paramount importance is the detailed shape of the Fermi surface and the accompanying Fermi velocity, since together they affect transport and other phenomena. Methods to measure these quantities include various magneto-acoustic effects (e.g., the geometric resonance phenomenon), the Gantmakher and Sondheimer size effects, the Azbel–Kaner cyclotron resonance, the anomalous skin effect, the high-field magneto-resistance (as it relates to open versus closed orbits), and various quantum oscillations, the most important of which is the de Hass–van Alphen effect. For determining the energy spectrum at energies below the Fermi surface, the most powerful technique is angle resolved photo-emission spectroscopy (ARPES) which, with the emergence of synchrotron sources, has become increasingly important. Also of growing importance is inverse photo-emission spectroscopy (IPS), a special case of which is termed bremsstrahlung isochromat spectroscopy (BIS). Here the roles of the incoming photon and the final state electron are reversed: electrons of known energy (and angle) impinge on the surface and (in the BIS variant) the energy spectrum of the emitted photons is measured. This technique probes the spectrum for energies above the Fermi energy.
Homogeneous Semiconductors
Authors: Ketterson J. B. 
Published: December 2016

Abstract
A semiconductor can be regarded as an insulator with a narrow band gap, εg. Semiconductors may be divided into two classes: those for which the points in k-space corresponding to the highest occupied valence band state, εv, and the lowest unoccupied conduction band state, εc, lie directly above each other (a direct band gap material); and those for which these two points are separated in k-space by some amount k0 (an indirect band gap material). At absolute zero, all the states associated with the valence bands are filled while those of the conduction bands are empty. The empty state is referred to as a hole. In the presence of an applied electric field, transitions will occur from the lower lying (occupied) electron state into the empty hole state, i.e., the hole will move lower in energy. However, since the hole represents the absence of an electron, this downward motion of the hole represents an increase in the energy of the system. In steady state, where the energy gained from an external potential drop is lost to the rest of the system through scattering, the hole will drift at a constant velocity. A completely filled band carries no current, and therefore the holes contribute a current of the opposite sign — they behave like positively charged electrons. This chapter discusses the following: parabolic bands, carrier densities and densities of states, band properties in some specific materials, holes in Si and Ge, impurity states, calculating the occupancy of donors and acceptors, carrier concentrations in the presence of donors and acceptors, impurity band conduction, and qualitative behavior on doping.
Inhomogeneous Semiconductors
Authors: Ketterson J. B. 
Published: December 2016

Abstract
This chapter begins by analyzing p–n junctions in equilibrium and in the presence of an electric field. A device called a diode, which possesses asymmetric characteristics for current flow in opposite directions, is made by forming a junction between a p-type material (containing only acceptor levels) and an n-type material (containing only donors). After contact, the materials come into chemical equilibrium by the exchange of electrons until their chemical potentials equilibrate. A more detailed theory of current transport in a p–n junction both in equilibrium and under an applied voltage is developed followed by discussions of the operation of a number of semiconductor devices. These include the diode rectifier, the p–n–p junction transistor, the tunnel diode, the junction laser, the Zener diode, the field effect transistor, and the MOSFET ((metal-oxide–semiconductor field effect transistor).
Electric and Magnetic Susceptibilities
Authors: Ketterson J. B. 
Published: December 2016

Abstract
This chapter begins by discussing the effects of an electric field. An external electric field, E, will exert a force on all the charged constituents of a material. This force results in a displacement of various charge centres that, in equilibrium and in an insulator, is balanced by fields induced by the displacements themselves; at finite frequencies one must also account for the inertia (mass) associated with the accelerated nuclei and electrons making up the system, ultimately in a manner consistent with quantum mechanics. Such charge displacements in the body produce dipole moments. To account for the effect of these dipoles one introduces a polarization, defined as the dipole moment per unit volume. The electric field also produces a force on all the electrons. The strong nuclear electric field tightly constrains the motion of the core electrons; their orbitals are nonetheless distorted by the external field resulting in a core contribution to the electronic polarization. The remainder of the chapter deals with static ionic polarizibility; the electronic polarizibility of atoms and molecules; and the magnetic susceptibility of atoms and molecules.
Optical Responses
Authors: Ketterson J. B. 
Published: December 2016

Abstract
Important information about the excitation spectra of semiconductors and insulators can be obtained by studying the frequency dependence of the absorption of light passing through the material. This chapter first introduces the matrix element for optical absorption spectra. At low temperatures, transitions take place only between the occupied valence band states and the unoccupied conduction band states. An expression is developed for the transition probability per unit time between two such states, wherein a matrix element — involving the perturbation Hamiltonian in Chapter 24 — connects the initial (valence band) state and the final (conduction band) state. The remainder of the chapter discusses the singular points in the optical absorption; the frequency-dependent susceptibility; some analytic properties of the susceptibility; the Kramers–Kronig relations; and some examples of optical spectra. Sample problems are also provided at the end of the chapter.
Polaritons, Excitons, and Plasmons
Authors: Ketterson J. B. 
Published: December 2016

Abstract
This chapter begins by deriving the Lyddane–Sachs–Teller relation. It then turns to excitons, which refer to states produced by a kind of excitation wherein an electron and hole are created, but they do not escape their mutual Coulomb attraction and end up in a bound electron–hole state. The binding energy and characteristic size of excitons varies widely among different materials. We may construct simple models for the limiting cases where the size of the excitons is much larger than, or of the order of, the spacing between the atoms. These limiting cases are referred to as Wannier and Frankel excitons, respectively, each of which is discussed in turn. The remainder of the chapter covers the exciton–polariton, plasmons, and surface polaritons. Sample problems are also given at the end of the chapter.
Behavior Under Intense Illumination: NLO, the e–h Liquid and Excitonic BEC
Authors: Ketterson J. B. 
Published: December 2016

Abstract
Chapter 29 examined the linear response of insulators and semiconductors to light, particularly with respect to optical absorption. With the availability of high intensity pulsed lasers it is now possible to study responses in the nonlinear regime where phenomena such as harmonic generation and frequency mixing occur as well as collective behaviors of the high densities of excitations being reduced. The latter is of interest in connection with the electron–hole liquid and Bose–Einstein condensation (BEC) of excitons, both of which are discussed in this chapter. Topics covered include the effects on quadratic (second order) and cubic (third order) susceptibilities on harmonic fields; Bose condensation in an ideal gas; the weakly interacting Bose gas for non-zero temperatures; and the Gross–Pitaevskii equation.
A Phenomenological Theory of Superconductivity: The Ginzburg–Landau Theory and the Josephson Effects
Authors: Ketterson J. B. 
Published: December 2016

Abstract
This chapter begins with an analysis of Ginzburg–Landau theory. The discussion in Chapter 32 has brought out the idea that superconductivity is some kind of macroscopic quantum state. Ginzburg and Landau built this idea into the Landau second-order phase transition theory by assuming the existence of a macroscopic ‘wave function’, which they took as the order parameter associated with superconductivity. The chapter then discusses boundaries and boundary conditions, the upper critical field and the phase diagram of a type II superconductor, the Josephson effects, magnetic field effects, and the behaviour of a single planar Josephson junction in a magnetic field. A sample problem is also provided at the end of the chapter.
Econometrics of Panel Data
Authors: Biørn Erik 
Published: December 2016

AbstractPanel data is a data type increasingly used in research in economics, social sciences, and medicine. Its primary characteristic is that the data variation goes jointly over space (e.g. individuals, firms, countries) and time (e.g. years, months). Panel data allow examination of problems which cannot be handled by cross-section data or time-series data. Panel data analysis is a core field in modern econometrics and multivariate statistics, and studies based on such data occupy a growing part of the field in many other disciplines. The book is intended as a text for master’s/advanced undergraduate courses. It may also be useful for PhD students writing theses in empirical/applied economics and readers doing empirical work on their own. The book attempts to take the reader gradually from simple models and methods in scalar (simple vector) notation to more complex models in matrix notation. Compared to related texts, a distinctive feature is that relatively more attention is given to unbalanced panel data, the measurement error problem, random coefficient approaches, the interface between panel data and aggregation, and the interface between unbalanced panels and truncated and censored data sets. The 12 chapters are intended to be largely self-contained, although there is a natural progression. Most chapters contain commented examples based on genuine data, mainly taken from panel data applications to economics. Although the book, inter alia, through its use of examples, aims primarily at students of economics/econometrics, it may be useful also for readers in social sciences outside economics and in psychology and medicine, provided they have a sufficient background in statistics, notably basic regression analysis and elementary linear algebra.
Regression analysis with unidimensional variables
Authors: Biørn Erik 
Published: December 2016

AbstractThis chapter introduces the reader to the basic properties of second-order moments and moment matrices involving unidimensional variables. One-way and two-way regression models containing unobserved fixed or random effects jointly with unidimensional regressors are considered. For the fixed effects versions, notable collinearity and identification problems arise, which may restrict the attraction of such models, are considered.
Dynamic models
Authors: Biørn Erik , Biørn Erik , Biørn Erik 
Published: December 2016

AbstractThe chapter considers first-order autoregressive models with individual-specific intercepts. Both the within estimator and OLS estimation of an equation in first-differences have notable deficiencies when the time-series are short. More relevant are estimators utilizing instrumental variables (IV) in levels for the equation in differences, or estimators using the opposite configuration. Procedures using orthogonal forward deviations are also considered. Versions of GMM are discussed, and extensions to handle disturbance memory are explained. For models with random effects, Maximum Likelihood (ML) and stepwise procedures are considered for equations containing both two-dimensional and individual-specific explanatory variables.
Rex Leptasta (Hist. II, 20)
Authors: Syme Ronald 
Published: December 2016

Abstract
This passage provides a discussion of a fragment of Sallust’s Histories that sheds light on an aspect of the Roman presence in Spain and North Africa, and of the history of the Sertorian War. The discussion deals with the wider strategy of Sertorius in the war against Rome and with the role that some sectors of the provincial elites played in that context. The figure of Vibius Paciaecus receives close consideration, as well as the place of the historian Fenestella in the tradition on Spain the late Republican period. A passage of Plutarch’s Life of Crassus suggests that the influence of this author was quite considerable, and that he had good first-hand knowledge of that region.