bluuebunny/crossref_metadata_2025_split huggingface dataset:
How to write a class
Authors: Boudreau Joseph F. , Swanson Eric S. 
Published: February 2018

Abstract
While there is no such thing as a “typical” C++ class, several common syntactical constructs lend themselves to extremely widespread use and must be mastered by C++ programmers. To motivate the discussion of software design at the level of the C++ class, examples from computer science and optics are introduced. Important syntactical elements such as constructors, destructors, copy constructors, assignment operators, cast operators, and const qualifiers, together with function overloading, operator overloading, and dynamic memory allocation are discussed. These concepts, illustrated with examples from physics, are presented and explained. Further examples from optical and quantum mechanical problems are left to the exercises. This chapter and its exercises gives the reader sufficient information to begin developing his or her own classes and to experiment with class design through trial and error.
Ordinary differential equations
Authors: Boudreau Joseph F. , Swanson Eric S. 
Published: February 2018

Abstract
This chapter surveys the ordinary differential equations (ODEs) that occur in classical and quantum mechanics, and describes both numerical algorithms and appropriate software design for solving them. Systems of ordinary differential equations, together with a few constants of integration, can in most cases be regarded as a means of defining a function (the “solution”). In this chapter, we develop an object-oriented architecture that applies integrators of the Runge-Kutta family to create these functions. Together with an automatic derivative system for generating partial derivatives from functions of one or more variables, the differential equation solver becomes a powerful tool for solving a variety of few-body problems in classical Hamiltonian systems. This chapter presents a blend of numerical algorithms, physics, and computing techniques. The phenomenon of energy drift is discussed and used to motivate symplectic solvers. Techniques such as adaptive step size and possible problems with stability and multiple scales are also discussed.
Data modeling
Authors: Boudreau Joseph F. , Swanson Eric S. 
Published: February 2018

Abstract
A variety of techniques for extracting information from data are presented, from pedestrian approaches such as the centuries old linear least-squares fit, to elegant binned and unbinned likelihood fits. A treatment of statistical combination of data leads to an introduction to the powerful Kalman filter approach, used to determine optimal estimates of deterministic-stochastic systems. In experimental physics the Kalman filter is used estimate trajectories from data, but it also finds applications in industrial process control, and in the aeronautics and robots industries. These techniques typically rely on either analytic or numerical optimization of an objective function. Orthogonal series density estimation, a Fourier technique, is also discussed.
Many body dynamics
Authors: Boudreau Joseph F. , Swanson Eric S. 
Published: February 2018

Abstract
Specialized techniques for solving the classical many-body problem are explored in the context of simple gases, more complicated gases, and gravitating systems. The chapter starts with a brief review of some important concepts from statistical mechanics and then introduces the classic Verlet method for obtaining the dynamics of many simple particles. The practical problems of setting the system temperature and measuring observables are discussed. The issues associated with simulating systems of complex objects form the next topic. One approach is to implement constrained dynamics, which can be done elegantly with iterative methods. Gravitational systems are introduced next with stress on techniques that are applicable to systems of different scales and to problems with long range forces. A description of the recursive Barnes-Hut algorithm and particle-mesh methods that speed up force calculations close out the chapter.
Quantum mechanics I–few body systems
Authors: Boudreau Joseph F. , Swanson Eric S. 
Published: February 2018

Abstract
Several techniques for obtaining the eigenspectrum and scattering properties of one- and two-body quantum systems are presented. More unusual topics, such as solving the Schrödinger equation in momentum space or implementing relativistic kinematics, are also addressed. A novel quantum Monte Carlo technique that leverages the similarity between path integrals and random walks is developed. An exploration of the method for simple problems is followed by a survey of methods to obtain ground state matrix elements. A review of scattering theory follows. The momentum space T-matrix formalism for scattering is introduced and an efficient numerical method for solving the relevant equations is presented. Finally, the method is extended to the coupled channel scattering problem.
Quantum spin systems
Authors: Boudreau Joseph F. , Swanson Eric S. 
Published: February 2018

Abstract
The quantum mechanical underpinnings of magnetism are explored via the Heisenberg model of antiferromagnetism. The Lanczos algorithm is developed and applied to obtain ground state properties of the anisotropic antiferromagnetic Heisenberg spin chain. In particular, the phase diagram for the system magnetization is determined. A quantum Monte Carlo method that is appropriate for discrete systems is also presented. The method leverages the similarity between the Schrödinger equation and the diffusion equation to compute energy levels. The formalism necessary to compute ground state matrix elements is also developed. Finally, the method is tested with an application to the spin chain.
The Interaction of Judicial and Legislative Policymaking
Authors: Schmidt Susanne K. 
Published: February 2018

Abstract
Chapter 4 systematizes the different ways that judicial policymaking can have an impact on European legislation. Identifying the codification of case-law principles in secondary law contributes to research on the EU in two important ways: it shows how EU legislation is embedded in case-law development, and that the impact of case law cannot be reduced to the question of compliance with single rulings. A differentiation is made between several types of judicial ‘shadow’ over the legislative process. Then the Services Directive and the regulation on the mutual recognition of goods are analysed. The principles of case law that were motivated by the specific circumstances of individual cases constrain the design of general rules. Secondary law cannot modify constitutional principles. At best, the legislature can hope to signal its political preferences to the Court.
Deep Impurities with Collision Delay
Authors: Morawetz Klaus 
Published: February 2018

AbstractThe linearised nonlocal kinetic equation is solved analytically for impurity scattering. The resulting response function provides the conductivity, plasma oscillation and Fermi momentum. It is found that virial corrections nearly compensate the wave-function renormalizations rendering the conductivity and plasma mode unchanged. Due to the appearance of the correlated density, the Luttinger theorem does not hold and the screening length is influenced. Explicit results are given for a typical semiconductor. Elastic scattering of electrons by impurities is the simplest but still very interesting dissipative mechanism in semiconductors. Its simplicity follows from the absence of the impurity dynamics, so that individual collisions are described by the motion of an electron in a fixed potential.
Relaxation-Time Approximation
Authors: Morawetz Klaus 
Published: February 2018

AbstractA conserving relaxation time approximation is presented resulting into a Mermin-type of polarisation functions. The transport properties are calculated for the relaxation time approximation and an arbitrary band structure. The results for metals and gases are discussed and the shortcoming of relaxation time approximation to describe experimental values is outlined. As improvement, the exact solution of the linearised quantum Boltzmann equation is presented leading to momentum-depended relaxation times specific for each observable. Explicit expressions are given for the electric and thermal conductivity as well as the shear viscosity.
Transient Time Period
Authors: Morawetz Klaus 
Published: February 2018

AbstractThe formation of correlations at short- time scales is considered. A universal response function is found which allows describing the formation of collective modes in plasmas created by femto-second lasers as well as the formation of occupations in cold atomic optical lattices. Quantum quench and sudden switching of interactions are possible to describe by such Levinson-type kinetic equations on the transient time regime. On larger time scales it is shown that non-Markovian–Levnson equations double count correlations and the extended quasiparticle picture to distinguish between the reduced density matrix and quasiparticle distribution solve this shortcoming. The problem of initial correlations and how they can be incorporated into the Green’s function technique to result into modified kinetic equations is solved and a systematic expansion is suggested.
Field-Dependent Transport
Authors: Morawetz Klaus 
Published: February 2018

AbstractUsing a gauge-invariant formulation of Green’s function, the electric-field dependent kinetic equations are derived in Born and RPA (dynamically screened) approximation. The feedback and Debye–Onsager relaxation effects are discussed and explicitly calculated for two- and three-dimensional systems. It is found that only the asymmetrically screened result in accordance with the asymmetric cummulant expansion of chapter 11 can describe the correct relaxation effect. The conductivity with electron-electron interaction is presented and the adiabatic as well as isothermal approximations introduced. All expressions are calculated for an example of a quasi two-dimensional electron gas.
Simulations of Heavy-Ion Reactions with Nonlocal Collisions
Authors: Morawetz Klaus 
Published: February 2018

AbstractThe scenario of heavy-ion reactions around the Fermi energy is explored. The quantum BUU equation is solved numerically with and without nonlocal corrections and the effect of nonlocal corrections on experimental values is calculated. A practical recipe is presented which allows reproducing the correct asymptotes of scattering by acting on the point of closest approach. The better description of dynamical correlations by the nonlocal kinetic equation is demonstrated by an enhancement of the high-energy part of the particle spectra and the enhancement of mid-rapidity charge distributions. The time-resolved solution shows the enhancement of neck formation. It is shown that the dissipated energy increases due to the nonlocal collision scenario which is responsible for the observed effects and not due to the enhancement of collisions. As final result, a method is presented how to incorporate the effective mass and quasiparticle renormalisation with the help of the nonlocal simulation scenario.
Agrarian Change and Structural Transformation: Drivers and Distributional Outcomes
Authors: Djurfeldt Agnes Andersson , Djurfeldt Göran , Hall Ola , Bustos Maria Archila 
Published: February 2018

Abstract
This chapter examines agrarian changes triggered by the structural transformation of the overall economy, focusing on their drivers and distributional outcomes. By means of multi-level modelling of three processes—intensification of grain yields, diversification of cropping, and non-farm diversification (pluriactivity)—it concludes that intensification has moderately accelerated and is getting more important than its twin process. Similarly, crop diversification has accelerated, while non-farm diversification seems to be more pull- than push-driven. The most important drivers of the two first-mentioned processes are commercial ones: increasing local and domestic demand for grains and for other crops and institutional changes promoting market participation of smallholders. The chapter concludes that these processes are not pro-poor, but neither are they pro-rich; middling smallholder households tend to be more involved. The gender profile of agricultural diversification seems to involve and benefit male-managed farms, whereas non-farm diversification is gender neutral.
Quantum mechanics
Authors: Kachelriess Michael 
Published: February 2018

Abstract
After a brief review of the operator approach to quantum mechanics, Feynmans path integral, which expresses a transition amplitude as a sum over all paths, is derived. Adding a linear coupling to an external source J and a damping term to the Lagrangian, the ground-state persistence amplitude is obtained. This quantity serves as the generating functional Z[J] for n-point Green functions which are the main target when studying quantum field theory. Then the harmonic oscillator as an example for a one-dimensional quantum field theory is discussed and the reason why a relativistic quantum theory should be based on quantum fields is explained.
Free scalar field
Authors: Kachelriess Michael 
Published: February 2018

Abstract
In this chapter, the path integral approach is extended from quantum mechanics to the simplest field theory containing a single real scalar field. First the generating functionals of (dis-) connected n-point Green functions are introduced, then the Feynman propagator of the scalar field is derived and causality is discussed. The exchange of a space-like scalar particle between two static sources is examined and it is shown that it leads to an attractive Yukawa potential. The Casimir effect is used to demonstrate that vacuum fluctuations have physical consequences.
Cosmological models for an homogeneous, isotropic universe
Authors: Kachelriess Michael 
Published: February 2018

Abstract
The universe is homogeneous and isotropic on sufficiently large scales. The metric which describes such a space-time is derived and it is shown that it is determined by the scale factor a(t) and the parameter k distinguishing between hyperbolic, flat, or spherical 3-spaces. The Friedmann equations, which describe the time evolution of these models, are derived and specific models are discussed.
Baryogenesis
Authors: Kachelriess Michael 
Published: February 2018

Abstract
This chapter shows that a baryon asymmetry can be generated only if the Sakharov conditions are satisfied. The required departure from thermal equilibrium can be realised either in first-order phase transitions or in out-of-equilibrium decays. Sphaleron transitions as a possible way to transfer a lepton into a baryon asymmetry are covered and the Boltzmann equation governing the baryon asymmetry generated in particle decays is derived. A brief review of baryogenesis during the electroweak phase transition is presented.
Quantum fields in curved spacetime
Authors: Kachelriess Michael 
Published: February 2018

Abstract
After a review of conformal symmetry, this chapter covers the quantisation of fields in curved space-times. It is shown that field operators defined with respect to different vacua are related by a Bogolyubov transformation and that the mixing of positive and negative frequencies determines the amount of particle production. The Unruh effect is explained and it is shown that in a space-time with an event horizon, a thermal spectrum of particles is created close to the horizon.
European High-Skilled Migration Policy
Authors: Cerna Lucie 
Published: February 2018

The chapter argues that while Europe needs high-skilled immigrants to fill labour shortages and respond to ageing populations, it continues to struggle recruiting these immigrants due to incre	asing political tensions over immigration, which can also affect the highly skilled. These tensions are visible in the varying national policies and Blue Card versions at the EU level. The chapter analyses demographic, economic, and political challenges in Europe and traces high-skilled immigration policy developments over the last decade, both in terms of national policies and the adoption of the EU Blue Card. To demonstrate the variation in Blue Card versions, the chapter presents a newly developed Blue Card Index (BCI) and compares it with an existing index of national high-skilled immigration policies. The indices highlight considerable variation in national policies and Blue Card versions. This has important policy implications, which are discussed in the concluding section.
Effectiveness of Vaginal Breech Birth Training Strategies: An Integrative Review of the Literature
Authors: Walker S. , Breslin E. , Scamell M. , Parker P. 
Published: February 2018

(Birth. 2017;44(2):101–109)
Although most breech-presenting infants are born by cesarean section, the latest Cochrane Review on term breech delivery emphasized the importance of skills to facilitate vaginal breech birth and highlighted those skills as a research priority. The present integrative review aimed to identify and assess the effectiveness of breech birth training strategies according to the 4 levels of Kirkpatrick’s levels of evaluation (reaction, learning, behavior, and results), and included both intended and unintended outcomes, as recommended by Yardley and Dornan. An additional objective of the present review was to gain insight into effective strategies of education about breech vaginal births.
Management of Pregnancies Complicated by Hypertensive Disorders of Pregnancy: Could we do Better?
Authors: Helou A. , Walker S. , Stewart K. , George J. 
Published: February 2018

(Aust N Z J Obstet Gynaecol. 2017;57(3):253–259)
Hypertensive disorders are associated with fetal growth restriction and premature birth as well as increased rates of maternal mortality and morbidity. Active optimization of management is an important part of the antenatal care of pregnant women with hypertensive disorders. Compliance with clinical guidelines for the management of hypertension during pregnancy can positively affect maternal and perinatal outcomes.
Gestational Diabetes in the United States: Temporal Changes in Prevalence Rates Between 1979 and 2010
Authors: Lavery J.A. , Friedman A.M. , Keyes K.M. , Wright J.D. , Ananth C.V. 
Published: February 2018

(BJOG. 2017;124:804–813)
Gestational diabetes mellitus (GDM) is one of the most common conditions complicating pregnancy, affecting an estimated 8.3% of pregnancies worldwide and 3% to 4% of pregnancies in the United States. Not only are women with GDM more likely to develop type-II diabetes later in life, but they are also at increased risk for preeclampsia and gestational hypertension in subsequent pregnancies. As a result of women with pregnancies complicated by GDM being more likely to have large for gestational age (LGA) infants, they have an increased risk of being delivered via cesarean section and or suffering birth injury.
Complications of External Cephalic Version: A Retrospective Analysis of 1121 Patients at a Tertiary Hospital in Sydney
Authors: Rodgers R. , Beik N. , Nassar N. , Brito I. , de Vries B. 
Published: February 2018

(BJOG. 2017;124(5):767–772)
There has been substantial debate regarding the most appropriate mode of delivery for a term breech baby. The Term Breech Trial (2000) found significantly lower perinatal and neonatal mortality as well as serious neonatal morbidity in the planned cesarean-section group compared with the planned vaginal-birth group. As a result of this study, in developed countries delivery of term breech infants is now mainly by elective cesarean section. From the maternal standpoint, however, cesarean section is associated with increased maternal morbidity and mortality and a longer maternal recovery time compared with vaginal birth.
Leading Causes of Preterm Delivery as Risk Factors for Intraventricular Hemorrhage in Very Preterm Infants: Results of the EPIPAGE 2 Cohort Study
Authors: Chevallier M. , Debillon T. , Pierrat V. , Delorme P. , Kayem G. , Durox M. , Goffinet F. , Marret S. , Ancel P.Y. 
Published: February 2018

(Am J Obstet Gynecol. 2017;216(5):518.e1–518.e12)
Advances in care have resulted in large decreases in mortality and disability rates for preterm infants. While significant reductions in the rates of cerebral palsy have been seen, there has been no similar reduction in intraventricular hemorrhage (IVH), which is aggravated by weaknesses in the germinal matrix, changes in cerebral blood flow, and coagulation problems. Although the association of postnatal factors with IVH have been studied, the fact that the condition occurs within a few days of delivery implies that perinatal causes may be more important. In particular, the effect of pregnancy complications has not been studied. This study compared the incidence of IVH with the primary causes of preterm delivery.
Cesarean Delivery in the Second Stage of Labor and the Risk of Subsequent Premature Birth
Authors: Wood S.L. , Tang S. , Crawford S. 
Published: February 2018

(Am J Obstet Gynecol. 2017;217(1):63.e1–63.e10)
Cesarean delivery rates are on the rise in the United States, in part because of the increased use of cesarean delivery rather than forceps and vacuum deliveries for fetal distress and arrest disorders in the second stage of labor. However, cesarean delivery in the second stage of labor can be risky due to the difficulty of delivering a deeply impacted fetal head. Cohort studies have shown increased risk of extensions of the uterine incision, bladder injury, and postpartum hemorrhage in such deliveries. Surgical trauma to the cervix from other procedures has been demonstrated to significantly increase the risk of subsequent premature delivery. For these reasons, the authors hypothesized that second-stage cesarean deliveries may increase the rate of subsequent spontaneous preterm delivery.
Safety and Effectiveness of Alveolar Recruitment Maneuvers and Positive End-expiratory Pressure During General Anesthesia for Cesarean Section: A Prospective, Randomized Trial
Authors: Aretha D. , Fligou F. , Kiekkas P. , Messini C. , Panteli E. , Zintzaras E. , Karanikolas M. 
Published: February 2018

(Int J Obstet Anesth. 2017;30:30–38)
General anesthesia (GA) is sometimes associated with impaired oxygenation. Changes in respiratory mechanics and lung function under anesthesia contribute to this, with atelectasis being one of the most common etiologies of decreased oxygenation during GA. The supine position required during cesarean delivery results in decreased functional residual capacity and impaired lung compliance, as does the gravid uterus. Therefore, this patient population may be more likely to develop clinically significant atelectasis during general anesthesia. Alveolar recruitment maneuvers (ARM) with positive end-expiratory pressure (PEEP) along with low tidal volumes, considered a lung-protective ventilation strategy, can improve lung function and oxygenation and are frequently used for critically ill patients with respiratory distress syndrome. ARM with PEEP has also been shown to improve oxygenation and lung compliance in patients during general anesthesia. The current study was undertaken to test the hypothesis that ARM with PEEP and low tidal volume could improve intraoperative lung dynamic compliance during GA for cesarean delivery.