bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social networks, time homeless, and social support: A study of men on Skid Row
Authors: GREEN HAROLD D. , TUCKER JOAN S. , GOLINELLI DANIELA , WENZEL SUZANNE L. 
Published: December 2013

AbstractHomeless men are frequently unsheltered and isolated, disconnected from supportive organizations and individuals. However, little research has investigated these men's social networks. We investigate the structure and composition of homeless men's social networks, vis-a-vis short- and long-term homelessness with a sample of men drawn randomly from meal lines on Skid Row in Los Angeles. Men continuously homeless for the past six months display networks composed of riskier members when compared to men intermittently homeless during that time. Men who report chronic, long-term homelessness display greater social network fragmentation when compared to non-chronically homeless men. While intermittent homelessness affects network composition in ways that may be addressable with existing interventions, chronic homelessness fragments networks, which may be more difficult to address with those interventions. These findings have implications for access to social support from network members which, in turn, impacts the resources homeless men require from other sources such as the government or non-governmental organizations.
Policy, Politics and Political Science
Authors: Atkinson Michael M. 
Published: December 2013

Abstract.Political scientists are increasingly studying public policy in interdisciplinary environments where they are challenged by the political and normative agenda of other disciplines. Political science has unique perspectives to offer, including a stress on the political feasibility of policy in an environment of power differentials. Our contributions should be informed by the insights of cognitive psychology and we should focus on improving governance, in particular the competence and integrity of decision makers. The discipline's stress on legitimacy and acceptability provides a normative anchor, but we should not over invest in the idea that incentives will achieve normative goals. Creating decision situations that overcome cognitive deficiencies is ultimately the most important strategy.Résumé.Les politologues étudient les politiques publiques dans des contextes de plus en plus interdisciplinaires, où ils sont remis en question par les préoccupations politique et normatives d'autres disciplines. La science politique a des perspectives uniques à offrir, y compris un accent sur la faisabilité politique des politiques publiques dans un contexte de relations de pouvoir asymétriques. Nos contributions doivent être informées par les idées associées à la psychologie cognitive et nous devrions nous concentrer sur l'amélioration de la gouvernance, et notamment la compétence et l'intégrité des décideurs. L'accent de notre discipline sur la légitimité et l'acceptabilité fournit un point d'ancrage normatif, mais il ne faut pas trop investir dans l'idée que des mesures incitatives permettront nécessairement d'atteindre des objectifs normatifs. Créer des situations de décision qui surmontent les lacunes cognitives des acteurs est finalement la stratégie la plus importante à adopter.
Pete's bar: alternative use of the laryngoscopy suspension bar to improve surgical exposure during small incision cochlear implantation
Authors: MacKeith S A C , Sleeman-Barker P , Ramsden J D 
Published: December 2013

AbstractBackground:Cochlear implant surgery is increasingly being performed through a small incision because of the benefits associated with this technique, such as fewer wound complications. Efforts have been made to maximise surgical exposure in order to improve this evolving technique; this includes the development and use of new retractors. For instance, elasticated stay hooks can retract skin in a radial fashion and they are less bulky than traditional retractors. These hooks are usually attached directly to surgical drapes or to a disposable retractor ring; there are disadvantages to both of these methods.Method:This paper describes a technique using a laryngeal suspension bar in which the bar acts as a fixed structure to which these elasticated stay hooks can be attached.Conclusion:This technique was found to be safer, cheaper and more effective for obtaining optimal surgical exposure compared with a technique whereby the stay hooks are attached directly to the drapes or to a disposable retractor ring.
Dung beetles and fecal helminth transmission: patterns, mechanisms and questions
Authors: NICHOLS ELIZABETH , GÓMEZ ANDRÉS 
Published: December 2013

SUMMARYDung beetles are detrivorous insects that feed on and reproduce in the fecal material of vertebrates. This dependency on vertebrate feces implies frequent contact between dung beetles and parasitic helminths with a fecal component to their life-cycle. Interactions between dung beetles and helminths carry both positive and negative consequences for successful parasite transmission, however to date there has been no systematic review of dung beetle-helminth interactions, their epidemiological importance, or their underlying mechanisms. Here we review the observational evidence of beetle biodiversity–helminth transmission relationships, propose five mechanisms by which dung beetles influence helminth survival and transmission, and highlight areas for future research. Efforts to understand how anthropogenic impacts on biodiversity may influence parasite transmission must include the development of detailed, mechanistic understanding of the multiple interactions between free-living and parasitic species within ecological communities. The dung beetle–helminth system may be a promising future model system with which to understand these complex relationships.
Anaphylactic shock after amiodarone infusion resulting in haemodynamic collapse requiring a temporary ventricular assist device
Authors: Averin Konstantin , Lorts Angela , Connor Chad 
Published: December 2013

AbstractAcute heart failure related to anaphylactic shock is often reversible and necessitates aggressive support to ensure full recovery. We report the case of a 15-year-old boy who developed severe ventricular dysfunction and haemodynamic instability after administration of amiodarone and required temporary mechanical circulatory support with a left ventricular assist device. He had full recovery of cardiac function and returned to baseline neurologic status. This is the first report of successful left ventricular assist device use for recovery from cardiovascular collapse due to anaphylaxis.
Biological radiation dose from secondary particles in a Milky Way gamma-ray burst
Authors: Atri Dimitra , Melott Adrian L. , Karam Andrew 
Published: December 2013

AbstractGamma-ray bursts (GRBs) are a class of highly energetic explosions emitting radiation in a very short timescale of a few seconds and with a very narrow opening angle. Although, all GRBs observed so far are extragalactic in origin, there is a high probability of a GRB of galactic origin beaming towards the Earth in the past ∼0.5 Gyr. We define the level of catastrophic damage to the biosphere as approximation 100 kJ m−2, based on Thomas et al. (2005a, b). Using results in Melott & Thomas (2011), we estimate the probability of the Earth receiving this fluence from a GRB of any type, as 87% during the last 500 Myr. Such an intense burst of gamma rays would ionize the atmosphere and deplete the ozone (O3) layer. With depleted O3, there will be an increased flux of Solar UVB on the Earth's surface with potentially harmful biological effects. In addition to the atmospheric damage, secondary particles produced by gamma ray-induced showers will reach the surface. Among all secondary particles, muons dominate the ground-level secondary particle flux (99% of the total number of particles) and are potentially of biological significance. Using the Monte Carlo simulation code CORSIKA, we modelled the air showers produced by gamma-ray primaries up to 100 GeV. We found that the number of muons produced by the electromagnetic component of hypothetical galactic GRBs significantly increases the total muon flux. However, since the muon production efficiency is extremely low for photon energies below 100 GeV, and because GRBs radiate strongly for only a very short time, we find that the biological radiation dose from secondary muons is negligible. The main mechanism of biological damage from GRBs is through Solar UVB irradiation from the loss of O3 in the upper atmosphere.
Pharmacometrics and Systems Pharmacology Software Tutorials and Use: Comments and Guidelines for PSP Contributions
Authors: Vicini P , Friberg LE , van der Graaf PH , Rostami‐Hodjegan A 
Published: December 2013

In addition to methodological Tutorials,1 CPT:PSP has recently started to publish software Tutorials.2,3 Our readership and authors may be wondering what kind of format or product is expected, and the review of submissions we have already received prompted several discussions within the PSP Editorial Team. This editorial reflects on these discussions and summarizes their salient points. It aims at providing some details about the current vision of CPT:PSP for software tutorial articles. In addition, it brings some clarity on the topic of what role commercial software tutorials can have in CPT:PSP and how CPT:PSP tutorials differ from publications which describe the software itself, as those which can be found in other computer science journals. Finally, the discussion includes reproducibility considerations and the general use of commercial and noncommercial software in CPT:PSP publications. We hope our thoughts, and especially a stated requirement to publish user input to the software to aid in reproducibility, will help in guiding our authors and will stimulate healthy debate among our readers about the evolving nature of our science, how it can be facilitated using software and associated databases as a conduit, and what role this journal can play in fostering both the best modeling and simulation practices and the best scientific approaches to computational modeling, to bring the advantages of modeling and simulation to all regular practitioners, and not to just a (self) selected few.CPT Pharmacometrics Syst. Pharmacol. (2013) 2, e86; doi:10.1038/psp.2013.60; published online 18 December 2013
Cumulative latency advance underlies fast visual processing in desynchronized brain state
Authors: Wang Xu-dong , Chen Cheng , Zhang Dinghong , Yao Haishan 
Published: December 2013

Significance
Fast sensory processing, critical for the survival of animals, is usually achieved in a vigilant state characterized by cortical desynchronization. To understand the neural substrate for such fast processing, we examined brain state modulation of response latency in rat primary visual cortex (V1). We found that the response latency for V1 neurons is shorter in the desynchronized state than in the synchronized state. Increase in membrane conductance of single V1 neurons contributes to but cannot fully account for the observed latency advance. Such faster response is explained by cumulative latency advance along various stages of the visual pathway, from lateral geniculate nucleus to successive V1 layers, likely due to a global increase of membrane conductance in the desynchronized state.
Absence of splash singularities for surface quasi-geostrophic sharp fronts and the Muskat problem
Authors: Gancedo Francisco , Strain Robert M. 
Published: December 2013

Significance
The formation of singularities for the evolution of the interphase between fluids with different characteristics is a fundamental problem in mathematical fluid mechanics. These contour dynamics problems are given by fundamental fluid laws such as Euler’s equation, Darcy’s law, and surface quasi-geostrophic (SQG) equations. This work proves that contours cannot intersect at a single point while the free boundary remains smooth—a “splash singularity”—for either the sharp front SQG equation or the Muskat problem. Splash singularities have been shown for water waves. The SQG equation has seen numerical evidence of single pointwise collapse with curvature blow-up. We prove that maintaining control of the curvature will remove the possibility of pointwise interphase collapse, confirming the numerical experiments.
2 Introduction to Lagrangian Mechanics
Authors: Johns Oliver Davis 
Published: December 2013

AbstractThis chapter argues that modern analytical mechanics began with the work of the eighteenth-century mathematicians who elaborated Newton's ideas. Without changing Newton's fundamental principles, Euler, Laplace, and Lagrange developed elegant computational methods for the increasingly complex problems to which Newtonian mechanics was being applied. The Lagrangian formulation of mechanics is merely an abstract way of writing Newton's second law. When simple Cartesian coordinates are replaced by the most general variables capable of describing the system adequately, the Lagrange equations do not change. The vector methods fail when a mechanical system is described by systems of coordinates much more general than the standard curvilinear ones. The Lagrangian method frees one from the task of keeping track of the components of force vectors and the identities of the particles upon which they act.
4 Introduction to Hamiltonian Mechanics
Authors: Johns Oliver Davis 
Published: December 2013

AbstractThis chapter argues that Hamiltonian mechanics is a much better base from which to build more advanced methods. The Hamilton equations have an elegant symmetry that the Lagrange equations lack. The Hamiltonian function is also used to write the Schroedinger equation of quantum mechanics. The differences between the Lagrange and Hamilton equations result mainly from the different variable sets in which they act. The Lagrangian variable set is the set of generalised coordinates and velocities, whereas the Hamiltonian set is the set of generalised coordinates and momenta. The transformation from Lagrange to Hamilton equations is a Legendre transformation, in which the Lagrangian function of the Lagrangian variable set is to be replaced by the Hamiltonian function of the phase-space variable set.
The Calculus of Variations
Authors: Johns Oliver Davis 
Published: December 2013

AbstractThis chapter introduces the calculus of variations in the context of finite-dimensional configuration spaces. Mastery of this relatively simple form of the theory will provide the background required to study more advanced topics such as the variations of fields in the complex spaces of quantum field theory. The presentation of the calculus of variations here uses the so-called General Parametric Method. In it, a path is specified parametrically, by letting each of its coordinates be a function of some monotonically varying, but initially unspecified, parameter. This method contrasts with some other textbooks in which one of the coordinates is used as the parameter, and the other variables are made functions of it. The two methods are compared in detail in the sections that follow.
11 Central Force Motion
Authors: Johns Oliver Davis 
Published: December 2013

AbstractThis chapter applies a combination of vector mechanics and Lagrangian mechanics to the general system of two point masses interacting by a central force depending only on their separation. The special case of an inverse square central force reproduces Newton's achievement in modern notation. Newton's Principia presented proof that elliptical orbits are a natural consequence of an inverse square gravitational attraction between the sun and the planets, and launched the topic of discussion in this chapter. The central force problem is thus central to the early history of analytical mechanics. An inverse square central force is also found between charged particles in electrodynamics. The orbital motion of an electron around a proton underlies both the Bohr model of the hydrogen atom and the old quantum theory that was superseded by Schroedinger's quantum mechanics.
Scattering
Authors: Johns Oliver Davis 
Published: December 2013

AbstractThis chapter considers a class of experiments in which the event of interest is the scattering, or deflection, of initial velocity into some final velocity, of the beam particles into a range of directions. A classical accelerator experiment directs a beam of particles, idealised here as having uniform particle volume density and velocity across the beam, into a target region where interaction between beam particles and target particles produces an outcome event of interest. The rate of occurrence of such events is then measured. An experiment often has a number of mutually exclusive outcome events. Partial events are still reported as ‘cross sections’, and in most cases, ‘cross sections’ are merely numbers that are conventionally used to report the results of experiments and serve as a common interface between theory and experiment.
14 Hamiltonian Mechanics with Time as a Coordinate
Authors: Johns Oliver Davis 
Published: December 2013

AbstractThis chapter uses the traditional Hamilton equations as the basis for an extended Hamiltonian theory in which time is treated as a coordinate. The traditional Hamilton equations, including the Hamiltonian form of the generalised energy theorem, will be combined into one set of extended Hamilton equations. The extended Hamilton theory developed in the chapter is of fundamental importance for the more advanced topics in mechanics. It is used to write the relativistically covariant Hamiltonian, which is then used to derive the Klein-Gordon equation of relativistic quantum mechanics. The extended Hamilton equations also provide the basis for the discussion of canonical transformations. The objective of extended Hamiltonian theory is to write the equations of motion in terms of an extended set of phase-space variables.
17 Fourvectors and Operators
Authors: Johns Oliver Davis 
Published: December 2013

AbstractThis chapter develops techniques that allow relativistically covariant calculations to be done in an elegant manner, and introduces fourvectors. These are analogous to the familiar vectors in three-dimensional Cartesian space – which will now be referred to as threevectors. The difference is that, in addition to the three spatial components, fourvectors will have an additional zeroth component associated with time which allows one to deal with the fact that the Lorentz transformation of special relativity transforms time as well as spatial coordinates. The theory of fourvectors and operators is presented using an invariant notation. Rather than considering a fourvector to be a set of components in some basis, it is considered to be something that models some physical property of the experiment under study and is independent of the choice of coordinate system.
18 Relativistic Mechanics
Authors: Johns Oliver Davis 
Published: December 2013

AbstractThis chapter discusses the modified version of Newton's laws of motion. The relativistically modified mechanics is presented and then recast into a fourvector form that demonstrates its consistency with special relativity. Traditional Lagrangian and Hamiltonian mechanics can incorporate these modifications, but the transition to a manifestly covariant Lagrangian and Hamiltonian mechanics requires use of the extended Lagrangian and Hamiltonian methods. The traditional Lagrange and Hamilton equations derived here are covariant in the sense that they reproduce the relativistically modified equations of motion. However, it is advantageous to write Lagrangian and Hamiltonian mechanics in a manifestly covariant form in which only invariants and fourvectors appear in the equations. The consistency with special relativity is then apparent by inspection.
Time-dependent quantum mechanics
Authors: Galitski Victor , Karnakov Boris , Kogan Vladimir , Galitski, Jr. Victor 
Published: December 2013

Abstract
This chapter analyzes problems related to the Schrödinger representation (the motion of wave packets); time-dependent observables (constants of motion); time-dependent unitary transformations (the Heisenberg picture of motion); the time-dependent Green function; and quasi-stationary and quasi-energy states (the Berry phase).
The Nature of Computation
Authors: Moore Cristopher , Mertens Stephan 
Published: December 2013

AbstractComputational complexity is one of the most beautiful fields of modern mathematics, and it is increasingly relevant to other sciences ranging from physics to biology. However, this beauty is often buried underneath layers of unnecessary formalism, and exciting recent results such as interactive proofs, phase transitions, and quantum computing are usually considered too advanced for the typical student. This book bridges these gaps by explaining the deep ideas of theoretical computer science in a clear fashion, making them accessible to non-computer scientists and to computer scientists who finally want to appreciate their field from a new point of view. It starts with a lucid explanation of the P vs. NP problem, explaining why it is so fundamental, and so hard to resolve. It then leads the reader through the complexity of mazes and games; optimisation in theory and practice; randomised algorithms, interactive proofs, and pseudorandomness; Markov chains and phase transitions; and the outer reaches of quantum computing. At every turn, it uses a minimum of formalism, providing explanations that are both deep and accessible.
The Basics
Authors: Moore Cristopher , Mertens Stephan 
Published: December 2013

AbstractThis chapter discusses the complexity of a problem by thinking about the best possible algorithm, or computer program, that solves it. It shows that computational complexity theory is not about how to write better programs, but about understanding the underlying structure of different problems as well as asking fundamental questions about them. The chapter first explains problems and solutions by considering a Eulerian path and a Hamiltonian path. It then examines Euclid's algorithm, time and space, and the notion of scaling in physics. It also analyzes the distinction between polynomial functions of n and exponential ones, why this distinction is very important, and why it is so robust with respect to changes in the definition of computation. Finally, the chapter looks at the tractability and mathematical insight into a problem's structure.
The Deep Question: P vs. NP
Authors: Moore Cristopher , Mertens Stephan 
Published: December 2013

AbstractThis chapter considers the consequences of the possibility that P is equal to NP. It examines why it is extremely difficult to prove that P is not equal to NP by focusing on a set of ‘metatheorems’ which show the inadequacy of most of the proof techniques that have been proposed thus far. It also looks at the internal structure of NP and highlights its subclasses that capture various types of mathematical proof. The chapter demonstrates that, unless P is equal to NP, problems float in limbo between P and NP-completeness. Moreover, it describes several situations in which lower bounds can be proven and shows that a problem is outside a certain complexity class, or that one class is strictly more powerful than another. It also proves that polynomial time is less powerful than exponential time. Finally, it explores loopholes that might exist in the P vs. NP question and explains why it will eventually be resolved.