bluuebunny/crossref_metadata_2025 huggingface dataset:
Activity, substrate selection, and effect of a simulated Amazon flood regime on the behaviour of the apple snail, Pomacea bridgesii
Authors: Watanabe Timoteo Tadashi , Hattori Gustavo Yomar , Sant'Anna Bruno Sampaio
Published: March 2015

This study investigated the behaviour of Pomacea bridgesii, describing the daily activity, substrate selection and the influence of the flood regime in the Amazon, the species’ native habitat. The present study described the daily activity and substrate selection, and evaluated the activity adaptations of the gastropods in a simulated flood-pulse regime. Gastropods were collected in Amazonas, Brazil, in June 2013. Assessments of the daily behaviour, substrate selection, and flood-pulse simulation were made in experimental water tanks. The snails were observed hourly for 48h, and their behaviour recorded on an ethogram. The snails were more active during the night, when up to 80% of them moved about. In general, during both day and night, the gastropods used the pebble substrate most often. Comparing the day periods, a significant proportion of the individuals that were using the pebbles moved to other substrates (t=5; d.f.=2; P=0.03). The interaction of the behaviour of P. bridgesii with the simulated flood-pulse regime showed a statistical difference between the dry period and the period of maximum water level. The water regime of the Amazon floodplain directly influenced the activity of P. bridgesii, with responses including self-burying and activity interruption, with the operculum closed to minimise water loss.
High clonality in Acropora palmata and Acropora cervicornis populations of Guadeloupe, French Lesser Antilles
Authors: Japaud A. , Bouchon C. , Manceau J.-L. , Fauvelot C.
Published: March 2015

Since the 1980s, population densities of Acroporidae have dramatically declined in the Caribbean Sea. Quantitative censuses of Acroporidae provide information on the number of colonies (i.e. ramets), but not on the number of genetically distinct individuals (i.e. genets). In this context, the aim of our study was to provide an overview of the genetic status of Acropora populations in Guadeloupe by examining the genotypic richness of Acropora palmata and Acropora cervicornis. Using 14 microsatellite loci, we found extremely low genotypic richness for both species from Caye-à-Dupont reef (i.e. 0.125 for A. palmata and nearly zero for A. cervicornis). Because genetic diversity contributes to the ability of organisms to evolve and adapt to new environmental conditions, our results are alarming in the context of ongoing global warming as long periods of clonal growth without sexual recruitment may lead to the extinction of these populations.
The influence of water quality on hyporheic invertebrate communities in agricultural catchments
Authors: Kibichii Samuel , Feeley Hugh B. , Baars Jan-Robert , Kelly-Quinn Mary
Published: March 2015

Despite knowing that agricultural practices affect river ecosystems, studies on water quality and associated hyporheic invertebrate communities are rare. Yet such knowledge is essential for sustainable use of agricultural and water resources. This study, carried out in the agricultural region of south-eastern Ireland in Spring 2007, examined the effect of water pollution on hyporheic fauna. Six river sites of known water quality were assigned to two treatments, namely, clean and polluted rivers. Two hyporheic habitats, below the wetted channel (hyporheic substream) and below the exposed gravel bank (parafluvial), were sampled within each treatment. Total invertebrate densities and richness, crustacean densities and richness, and densities of Ephemeroptera, Plecoptera and Trichoptera (EPT) were significantly reduced in polluted hyporheic and parafluvial habitats. A higher recorded concentration of nitrate in the polluted hyporheic substream habitats was a significant factor in determining the invertebrate assemblages, with reductions in total and crustacean densities, and EPT richness. Similarly, invertebrate density and richness were reduced in polluted parafluvial habitats, likely being related to agricultural intensity, management practices and reduced riparian buffering. This study highlights the direct effects of agricultural practices on the invertebrate communities of hyporheic habitats and emphasises the need for holistic management and conservation measures to ensure future protection.
Ribosomal frameshifting and dual-target antiactivation restrict quorum-sensing–activated transfer of a mobile genetic element
Authors: Ramsay Joshua P. , Tester Laura G. L. , Major Anthony S. , Sullivan John T. , Edgar Christina D. , Kleffmann Torsten , Patterson-House Jackson R. , Hall Drew A. , Tate Warren P. , Hynes Michael F. , Ronson Clive W.
Published: March 2015

Significance

Integrative and conjugative elements (ICEs) facilitate horizontal transfer of multiple genetic determinants. Here we show that a programmed ribosomal frameshift (PRF) contributes to the regulation of ICE transfer. The low-frequency PRF fuses the coding sequences of two genes, resulting in a single-protein Frameshifted excision activator (FseA) that activates ICE excision. An antiactivator, QseM, known to disrupt the quorum-sensing regulator TraR, also disrupted FseA. The evolved PRF site, together with the dual-target antiactivator, QseM, likely provides robust suppression of ICE transfer in the face of the inherent biological noise of quorum-sensing autoinduction. This work illustrates how a complex multipartite regulatory system has assembled through evolution to form a robust genetic toggle to control gene transcription and translation at both single-cell and cell-population levels.
SHALLOW CAVITIES IN MULTIPLE-PLANET SYSTEMS
Authors: Duffell Paul C. , Dong Ruobing
Published: March 2015

Large cavities are often observed in protoplanetary disks, which might suggest the presence of planets opening gaps in the disk. Multiple planets are necessary to produce a wide cavity in the gas. However, multiple planets may also be a burden to the carving out of very deep gaps. When additional planets are added to the system, the time-dependent perturbations from these additional satellites can stir up gas in the gap, suppressing cavity opening. In this study, we perform two-dimensional numerical hydro calculations of gap opening for single and multiple planets, showing the effect that additional planets have on the gap depths. We show that multiple planets produce much shallower cavities than single planets, so that more massive planets are needed in the multiple-planet case to produce an equivalent gap depth as in the single-planet case. To deplete a gap by a factor of 100 for the parameters chosen in this study, one only requires M

p
≈ 3.5 M

J
in the single-planet case, but much more massive planets, M

p
≈ 7 M

J
are required in the multiple-planet case. This requirement of high-mass planets implies that such planets may be detectable in the next generation of direct imaging projects, in gaps whose depths are constrained to be sufficiently deep by ALMA.
Probing Berezinskii–Kosterlitz–Thouless Phase Transition of Spin-Half XXZ Chain by Quantum Fisher Information*
Authors: Zheng Qiang , Yao Yao , Xu Xun-Wei
Published: March 2015

The Berezinskii–Kosterlitz–Thouless phase transition of spin-1/2 XXZ chain is reinvestigated by the quantum Fisher information. Quantum Fisher informations of the whole N sites and the partial N/3 sites display remarkably similar behaviors near the critical point. The critical exponent of quantum Fisher information is obtained as β = 0.47, which is consistent with the results obtained by the concurrence and quantum discord.
Effect of Different Environments on Multipartite Global Discord*
Authors: Xu Bao-Ming , Zou Jian , Li Jun-Gang , Shao Bin
Published: March 2015

We investigate the influences of non-Markovian dissipation and global dephasing process on the dynamical behaviors of global discord among four qubits. We find that for the non-Markovian dissipation model W state is the most robust to decoherence compared to Dicke and GHZ states; however, for the global dephasing model Dicke state is the most robust to decoherence among them. Also the dynamical behaviors of global quantum discord are quite different from that of the multipartite entanglement for the non-Markovian dissipation model, while they are very similar to each other for the global dephasing model.
Implementation of Positive Operator-Valued Measure in Passive Faraday Mirror Attack*
Authors: Wang Wei-Long , Gao Ming , Ma Zhi
Published: March 2015

Passive Faraday-mirror (PFM) attack is based on imperfect Faraday mirrors in practical quantum cryptography systems and a set of three-dimensional Positive Operator-Valued Measure (POVM) operators plays an important role in this attack. In this paper, we propose a simple scheme to implement the POVM in PFM attack on an Faraday–Michelson quantum cryptography system. Since the POVM can not be implemented directly with previous methods, in this scheme it needs to expand the states sent by Alice and the POVM operators in the attack into four-dimensional Hilbert space first, without changing the attacking effect by calculation. Based on the methods proposed by Ahnert and Payne, the linear-optical setup for implementing the POVM operators is derived. At last, the complete setup for realizing the PFM attack is presented with all parameters. Furthermore, our scheme can also be applied to realize PFM attack on a plug-and-play system by changing the parameters in the setup.
Effect of Anisotropic Spin-Orbit Coupling on the Ground State of Bose–Einstein Condensate in an External Potential*
Authors: He Wan-Quan , Gao Ri-Li , Zhang Pei , Bi Xiong-Wei , Pan Qing-Shan , Xu Shi-Juan
Published: March 2015

Spin-orbit coupled Bosonic atoms confined in external potentials open up new avenues for quantum-state manipulation and will contribute to the design and exploration of novel quantum devices. Here we consider a quasi-two-dimensional spin-orbit coupled Bose–Einstein condensate confined in an external harmonic potential, with emphasis on the effects of anisotropic spin-orbit coupling on the equilibrium ground-state structure of such a system. For the cases with spin-orbit coupling solely in x- or y-axis direction, the ground-state structure can develop to the well-known standing wave phase, in which the two components always form an alternative density arrangement. For a two-dimensional anisotropic spin-orbit coupling, the separated lumps first become bend, then form two rows of stripe structure along y direction with further increasing the strength of spin-orbit coupling in x-direction. Furthermore, the distance between these two rows of stripe structure is also investigated in detail.
Hard-Core Bosons on a Two-Dimensional Square Optical Superlattice*
Authors: Li Xiao-Juan , Wen Yu-Chuan
Published: March 2015

In this work, we theoretically study hard-core bosons on a two-dimensional square optical superlattice at T = 0. First of all, we present the mean field phase diagram of this model in terms of the chemical potential μ and the alternating potential strength Δ. Besides a superfluid (SF) phase at Δ = 0 and a charge density wave (CDW) phase in the large Δ at half filling, we demonstrate that a supersolid (SS) phase emerges in the moderate Δ. Then, we focus on the μ = 0, e.g., half filling case, using large-S semiclassical spin-wave approximation to study the SS to CDW quantum phase transition. In particular, we calculate the ground-state energy and the superfluid density at the level of 1/S correction. We then compare the spin-wave results with the large scale quantum Monte Carlo (QMC) simulations using the cluster stochastic series expansion (CSSE) algorithm, and find that while the spin wave method is intuitive with clear physical pictures, the quantum critical point is quite different from that of numerical results which is believed to be accurate. We suggest that as simple as it is, this model still exhibits strong quantum fluctuations near the quantum critical point beyond the power of semiclassical spin-wave approach.
Analysis of the Z(4430) as the First Radial Excitation of the Zc
(3900)*
Authors: Wang Zhi-Gang
Published: March 2015

In this article, we take the Zc(3900) and Z(4430) as the ground state and the first radial excited state of the axial-vector tetraquark states with JPC = 1+−, respectively, and study their masses and pole residues with the QCD sum rules by calculating the contributions of the vacuum condensates up to dimension-10 in a consistent way in the operator product expansion. The numerical result favors assigning the Zc(3900) and Z(4430) as the ground state and first radial excited state of the axial-vector tetraquark states, respectively.
Pair Production of the Doubly Charged Leptons Associated with a Gauge Boson γ or Z in e+e−
and γγ Collisions at Future Linear Colliders*
Authors: Zeng Qing-Guo , Ji Li , Yang Shuo
Published: March 2015

In this paper, we investigate the production of a pair of doubly charged leptons associated with a gauge boson V(γ or Z) at future linear colliders via e+e− and γγ collisions. The numerical results show that the possible signals of the doubly charged leptons may be detected via the processes e+e− → VX++X−− and γγ → VX++X−− at future ILC or CLIC experiments.
Superposition of Stationary Wave Fields Via Atom Microscopy
Authors: Hizbullah  , Anwar Ali khan , Naveed Khan , Iftikhar Ahmad , Bakht Amin Bacha
Published: March 2015

We investigate one-dimensional position microscopy of a three-level atom moving through a stationary wave region under the condition of electromagnetically induced transparency. The precise position information of an atom is observed on the resonance absorption and dispersion distribution spectrum of a weak probe field. Single and multiple localization peaks are observed in specific directions of the corresponding wave numbers and phase of the standing wave fields. The strength of space-independent Rabi frequency reduces the position uncertainty in the localized peaks without disturbing the probability of the atom. In a hot atomic medium the localized probability of an atom is reduced which depends upon the temperature of that medium. Our results provide useful applications in the development of laser cooling, atom nanolithography and Bose–Einstein condensation.
Physiological Transportation of Casson Fluid in a Plumb Duct
Authors: Noreen Sher Akbar , Butt Adil Wahid
Published: March 2015

This paper is devoted to a study of the peristaltic motion of a Casson fluid of a non-Newtonian fluid accompanied in a horizontal tube. To characterize the non-Newtonian fluid behavior, we have considered the Casson fluid model. Suitable similarity transformations are utilized to transform the governing partial differential momentum into the non-linear ordinary differential equations. Exact analytical solutions of these equations are obtained and are the properties of velocity, pressure and profiles are then studied graphically.
Quintessence Field as a Perfect Cosmic Fluid of Constant Pressure*
Authors: Liu Wen-Zhong , Ouyang Jun , Yang Huan-Xiong
Published: March 2015

We study the cosmology of a quintessence scalar field which is equivalent to a non-barotropic perfect fluid of constant pressure. The coincidence problem is alleviated by such a quintessence equation-of-state that interpolates between plateau of zero at large redshifts and plateau of minus one as the redshift approaches to zero. The quintessence field is neither a unified dark matter nor a mixture of cosmological constant and cold dark matter, relying on the facts that the quintessence density contrasts of sub-horizon modes would undergo a period of late-time decline and the squared sound speeds of quintessence perturbations do not vanish. What a role does the quintessence play is dynamic dark energy, its clustering could remarkably reduce the growth rate of the density perturbations of non-relativistic matters.
Feynman–Kac theorems for generalized diffusions
Authors: Ekström Erik , Janson Svante , Tysk Johan
Published: March 2015

We find Feynman–Kac type representation theorems for generalized diffusions. To do this we need to establish existence, uniqueness and regularity results for equations with measure-valued coefficients.
The AP2 clathrin adaptor protein complex regulates the abundance of GLR-1 glutamate receptors in the ventral nerve cord ofCaenorhabditis elegans
Authors: Garafalo Steven D. , Luth Eric S. , Moss Benjamin J. , Monteiro Michael I. , Malkin Emily , Juo Peter
Published: March 2015

Regulation of glutamate receptor (GluR) abundance at synapses by clathrin-mediated endocytosis can control synaptic strength and plasticity. We take advantage of viable, null mutations in subunits of the clathrin adaptor protein 2 (AP2) complex in Caenorhabditis elegans to characterize the in vivo role of AP2 in GluR trafficking. In contrast to our predictions for an endocytic adaptor, we found that levels of the GluR GLR-1 are decreased at synapses in the ventral nerve cord (VNC) of animals with mutations in the AP2 subunits APM-2/μ2, APA-2/α, or APS-2/σ2. Rescue experiments indicate that APM-2/μ2 functions in glr-1–expressing interneurons and the mature nervous system to promote GLR-1 levels in the VNC. Genetic analyses suggest that APM-2/μ2 acts upstream of GLR-1 endocytosis in the VNC. Consistent with this, GLR-1 accumulates in cell bodies of apm-2 mutants. However, GLR-1 does not appear to accumulate at the plasma membrane of the cell body as expected, but instead accumulates in intracellular compartments including Syntaxin-13– and RAB-14–labeled endosomes. This study reveals a novel role for the AP2 clathrin adaptor in promoting the abundance of GluRs at synapses in vivo, and implicates AP2 in the regulation of GluR trafficking at an early step in the secretory pathway.
SINC, a type III secreted protein of Chlamydia psittaci, targets the inner nuclear membrane of infected cells and uninfected neighbors
Authors: Mojica Sergio A. , Hovis Kelley M. , Frieman Matthew B. , Tran Bao , Hsia Ru-ching , Ravel Jacques , Jenkins-Houk Clifton , Wilson Katherine L. , Bavoil Patrik M.
Published: March 2015

SINC, a new type III secreted protein of the avian and human pathogen Chlamydia psittaci, uniquely targets the nuclear envelope of C. psittaci–infected cells and uninfected neighboring cells. Digitonin-permeabilization studies of SINC-GFP–transfected HeLa cells indicate that SINC targets the inner nuclear membrane. SINC localization at the nuclear envelope was blocked by importazole, confirming SINC import into the nucleus. Candidate partners were identified by proximity to biotin ligase-fused SINC in HEK293 cells and mass spectrometry (BioID). This strategy identified 22 candidates with high confidence, including the nucleoporin ELYS, lamin B1, and four proteins (emerin, MAN1, LAP1, and LBR) of the inner nuclear membrane, suggesting that SINC interacts with host proteins that control nuclear structure, signaling, chromatin organization, and gene silencing. GFP-SINC association with the native LEM-domain protein emerin, a conserved component of nuclear “lamina” structure, or with a complex containing emerin was confirmed by GFP pull down. Our findings identify SINC as a novel bacterial protein that targets the nuclear envelope with the capability of globally altering nuclear envelope functions in the infected host cell and neighboring uninfected cells. These properties may contribute to the aggressive virulence of C. psittaci.
Drosophila Cappuccino alleles provide insight into formin mechanism and role in oogenesis
Authors: Yoo Haneul , Roth-Johnson Elizabeth A. , Bor Batbileg , Quinlan Margot E.
Published: March 2015

During Drosophila development, the formin actin nucleator Cappuccino (Capu) helps build a cytoplasmic actin mesh throughout the oocyte. Loss of Capu leads to female sterility, presumably because polarity determinants fail to localize properly in the absence of the mesh. To gain deeper insight into how Capu builds this actin mesh, we systematically characterized seven capu alleles, which have missense mutations in Capu's formin homology 2 (FH2) domain. We report that all seven alleles have deleterious effects on fly fertility and the actin mesh in vivo but have strikingly different effects on Capu's biochemical activity in vitro. Using a combination of bulk and single- filament actin-assembly assays, we find that the alleles differentially affect Capu's ability to nucleate and processively elongate actin filaments. We also identify a unique “loop” in the lasso region of Capu's FH2 domain. Removing this loop enhances Capu's nucleation, elongation, and F-actin–bundling activities in vitro. Together our results on the loop and the seven missense mutations provides mechanistic insight into formin function in general and Capu's role in the Drosophila oocyte in particular.
Introduction
Authors: McCready E.
Published: March 2015

This chapter is an overview of the book. It provides a general introduction to the book’s content and motivates some of the theoretical moves made there. As it says, the main theme is how judgements about reliability manifest in the semantics and pragmatics of natural language, focusing on the experiential basis for judging cooperativity and the likelihood that a given information source will give accurate information. It also gives a road map to reading the book, a brief statement of chapter dependencies, and a bit of background.
Trust and reputations
Authors: McCready E.
Published: March 2015

This chapter explores the phenomena of hedging and disclaimers. It proposes an analysis of them on which they serve to protect the reputation of the speaker from damage resulting from speaking falsehoods. This view is formalized using a model of histories of behavior in repeated games, which can be used to make judgements about speaker reliability and cooperativity. The resulting analysis is extended to cases in which only certain parts of the game histories are used to judge reliability, and some additional issues are addressed.
Deriving hedged interpretations
Authors: McCready E.
Published: March 2015

This chapter addresses the question of how hedged interpretations are to be derived, given the lack of any expression with a meaning dedicated to expressing a hedge. It is argued that hedged interpretations are obtained by pragmatic reasoning from the incoherence of certain kinds of discourse moves, in a way dependent on the expression of Moorean paradoxes by means of non-asserted content. A formal model is provided.
The nature of evidentials
Authors: McCready E.
Published: March 2015

This chapter is an overview of the nature of evidentials and of some existing formal analyses of them. It begins with a definition of evidentials and some examples of them, and continues to a summary of semantic analyses of evidentials. This part focues on how existing analyses handle the two types of evidentials that have been shown to exist: so‐called illocutionary and epistemic evidentials. Finally, the treatment of evidentials in formal pragmatics is considered.
Using priorities
Authors: McCready E.
Published: March 2015

This chapter uses the model of chapter 7 to analyze the concept of best possible grounds for a speech act, an important one in the analysis of evidentials. It is argued that best possible grounds amounts to the most reliable source for a particular assertion, as computed on the basis of initial probabilities of reliability together with the history of interaction in the sense of the first part of the book. It is also shown how the history of reliability of a particular evidence source can influence future judgements about its reliability and the overall ordering of evidence sources.
Testimonial evidence
Authors: McCready E.
Published: March 2015

This chapter returns to the particular case of testimonial evidence and places the proposed account within the philosophical landscape of work on testimony. The approach is argued to be a hybrid of reductionist and anti-reductionist approaches from this perspective. Information states corresponding to sources of testimonial evidence are then introduced and used to solve a puzzle of testimonial evidence based on an anti-reductionist view of testimony. Finally, the chapter returns to the case of hedged assertion, and argues that hedged assertions are an information source of their own, making them parallel to evidentials in the formal analysis.
Proto-Indo-European, Greek, and primitive languages: the last 150 years
Authors: Probert Philomen
Published: March 2015

Chapter 2 introduces an old debate now enjoying a considerable revival: should we expect languages spoken a few thousand years ago, such as Proto-Indo-European, to be in some sense primitive languages? Should we expect them to be systematically less well-equipped than modern languages when it comes to means of forming subordinate clauses? Or should we assume that the uniformitarian principle holds in a strong form, with languages at this time depth conforming to a linguistic typology based on modern languages? In particular, the chapter introduces the way in which ancient Greek has been used in this debate, in the past and again very recently.
Approaches to Proto-Indo-European relative clauses
Authors: Probert Philomen
Published: March 2015

Chapter 3 introduces a long-standing debate about relative clause syntax in the prehistory of the Indo-European language family. Understanding the prehistory of the relative pronouns found in early attested Indo-European languages is usually seen as the key to understanding what, if anything, Proto-Indo-European had by way of relative clauses. Matters are complicated by the presence of two candidates for reconstructable Indo-European relative pronouns, found in different languages from one another. Some early attested Indo-European languages, including Greek, form relative clauses with reflexes of the Proto-Indo-European pronoun*(H)yo-, but others use reflexes of the Proto-Indo-European pronoun *kwi-/kwo-. This chapter surveys the debate as to whether either or both of these already functioned as a relative pronoun in Proto-Indo-European and if so, what relative clause syntax was involved. The chapter finishes by considering alternative approaches that avoid making relative pronouns the starting point for reconstructing relative clause syntax.
What is a relative clause?
Authors: Probert Philomen
Published: March 2015

Chapter 4 considers what is actually meant by the term ‘relative clause’, and lays out a tripartite classification into restrictive relative clauses (the cat whom I love), non-restrictive relative clauses (the cat, whom I love), and inherently maximalizing relative clauses (This was what he wanted). In a language that uses definite articles, a noun modified by a restrictive or non-restrictive relative clause can take a definite or indefinite article (compare the cat whom I love with a cat whom I love, and the cat, whom I love with a cat, whom I love). By contrast, an inherently maximalizing relative clause has something like the meaning of the definite article built into it: what he wanted means something like the thing which he wanted, not a thing which he wanted. This tripartite classification is current in linguistic work, and crucial to the synchronic and diachronic analysis offered in this book.
Conclusions
Authors: Probert Philomen
Published: March 2015

Chapter 15 draws together the synchronic and diachronic analysis of the book, and returns to the role of ancient Greek relative clauses in the debate about languages spoken a few thousand years ago. The evidence suggests, firstly and most importantly, that when ancient Greek texts appear on the scene, a system including a rather rich variety of relative clause types has been in place for a considerable time: relative clauses do not support the idea that languages spoken a few thousand years ago were systematically poorer in these particular linguistic resources than their descendants. On the other hand, languages do constantly change, and prehistoric Greek was no exception. The chapter draws the analysis of early Greek together with observations about relative clauses elsewhere in the Indo-European language family, especially Latin, Hittite, and Germanic, and concludes with some suggestions about relative clauses in, or near, Proto-Indo-European.
Superconductivity from repulsive interaction
Authors: Maiti S. , Chubukov A. V.
Published: March 2015

Whether or not electron–electron pairing by the nominally repulsive Coulomb interaction, can give rise to superconductivity by itself is reviewed. The generic scenario of the pairing by electron–electron interaction put forward by Kohn and Luttinger is considered, as are modern studies of the electronic mechanism of superconductivity in the lattice models for the cuprates, the Fe pnictides, and the doped graphene. In the range of interactions where these systems are metals and Mott physics does not play a crucial role, the pairing in all three classes of materials can be viewed as lattice version of Kohn–Luttinger physics, despite differences in pairing symmetries. Conditions under which pairing occurs are discussed, as are the need to perform either parquet renormalization-group analysis at weak coupling or introduce effective interaction mediated by pre-formed spin or charge fluctuations at a stronger coupling and the interplay between superconductivity and density-wave instabilities at weak coupling.
Superfluidity in ultracold atomic Fermi gases
Authors: Zwierlein Martin W.
Published: March 2015

This chapter reviews experimental studies of fermionic superfluidity in ultracold atomic gases. Scattering properties of ultracold atoms and Feshbach resonances are introduced. The basic theoretical framework is presented based on the Leggett ansatz that provides intuition into many of the observed phenomena. The various experimental observations related to fermion pair condensation and superfluidity are described. The thermodynamic measurements of strongly interacting Fermi gases are considered. Experiments on superfluidity in the presence of population imbalance are reviewed. These studies have led to the observation of the Clogston–Chandrasekhar (or Pauli) limit of fermionic superfluidity and to the identification of a novel attractive Fermi liquid of polaronic quasiparticles. Novel Fermi systems, such as Fermi gases in lower dimensions, optical lattices, dipolar Fermi gases, and spin–orbit coupled Fermi gases, are also touched on briefly.
Coherent exciton transport in semiconductors
Authors: Rontani Massimo , Sham L. J.
Published: March 2015

After reviewing the physical systems that may host exciton condensation, this chapter illustrates some recent proposals concerning the detection of coherent exciton flow. It focuses on the exciton analogues of two phenomena—Andreev reflection and the Josephson effect—which are hallmarks of superconducting behavior and stress the crucial differences between excitons and Cooper pairs. It shows that the excitonic insulator is the perfect insulator in terms of both charge and heat transport, with an unusually high resistance at the interface with a semimetal—the normal phase of the condensed state. Such behavior may be explained in terms of the coherence induced into the semimetal by the proximity of the exciton condensate. The exciton superflow may be directly probed in the case that excitons are optically pumped in a double-layer semiconductor heterostructure. The chapter proposes a correlated photon counting experiment for coupled electrostatic exciton traps.
Pairing and superfluidity of nucleons in neutron stars
Authors: Gezerlis A. , Pethick C. J. , Schwenk A.
Published: March 2015

This chapter surveys the current status of understanding of pairing and superfluidity of neutrons and protons in neutron stars from a theoretical perspective, with emphasis on basic physical properties. During the past two decades, the blossoming of the field of ultracold atomic gases and the development of quantum Monte Carlo methods for solving the many-body problem have been two important sources of inspiration, and the chapter describes how these have given insight into neutron pairing gaps. The equilibrium properties and collective oscillations of the inner crust of neutron stars, where neutrons paired in a 1S0 state coexist with a lattice of neutron-rich nuclei, are also described. While pairing gaps are well understood at densities less than one tenth of the nuclear saturation density, significant uncertainties exist at higher densities due to the complicated nature of nucleon–nucleon interactions, the difficulty of solving the many-body problem under these conditions, and the increasing importance of many-nucleon interactions. The chapter touches more briefly on the subject of pairing of neutrons in other angular momentum states, specifically the 3P2 state, as well as pairing of protons.
Four-dimensional variational data assimilation
Authors: Lorenc A. C.
Published: March 2015

In this chapter, four-dimensional variational data assimilation (4D-VAR) is discussed in the context of numerical weather prediction (NWP). The analysis step in an NWP data assimilation cycle combines observations with a background forecast. Plausible models of error distributions involve transforms and statistics to describe the structure of errors at one time, plus a forecast model constraining the time evolution. They allow a Bayesian derivation of equations for the optimal analysis, by minimizing a 4D-Var penalty function using an adjoint model. Difficulties with the deterministic best fit of a nonlinear NWP model are discussed and a statistical approach to 4D-VAR based on the extended Kalman filter is presented. Advanced extensions to 4D-VAR can allow for nonlinearities and non-Gaussian distributions, arising from the physical limits to humidity, and from the possibility of erroneous observations. Ensembles provide useful information about likely background errors, which can be used in hybrid ensemble–variational data assimilation.
Error dynamics in ensemble Kalman-filter systems
Authors: Houtekamer P.
Published: March 2015

In this chapter, an experimental environment built around the Lorenz III toy model is used to demonstrate some points concerning localization. In an ensemble Kalman filter, localization is almost always necessary because of restrictions on the size of the ensembles. In fact, localization is the key technique that makes the ensemble approximation to the Kalman filter computationally feasible. How localization is best applied depends on aspects of the model dynamics and the observational network. A reasonable choice often leads to a substantial improvement in performance. Fortunately, as shown in this chapter, the statistics from the ensemble itself can provide guidance in the selection of a reasonable localization method.
Error dynamics in ensemble Kalman filter systems
Authors: Houtekamer P.
Published: March 2015

This chapter compares results from the Canadian global ensemble Kalman filter (EnKF) with observations. This inevitably leads to discrepancies between the observed real atmosphere and its modelled equivalent. These discrepancies originate from system error. In a system simulation experiment, an attempt is made to obtain a coherent picture of the error evolution of a system. Errors can be due to things as different as an inappropriate closure assumption in a forecast model and inaccurate observations of surface pressure. This chapter first describes Monte Carlo methods in general to arrive at a definition of ‘system error’. This is followed by an elimination procedure. First, medium-range ensemble forecasts are used to quantify the understanding of weaknesses of the forecast model. Subsequently, consideration turns to the data-assimilation context to see what additional error sources must be present. The chapter ends with some speculation on the types of errors that should be included.
An introduction to inverse modelling and parameter estimation for atmosphere and ocean sciences
Authors: Bocquet M.
Published: March 2015

This chapter is a short survey of the inverse modelling and parameter estimation methods currently used in the atmosphere and ocean sciences. The focus is on the estimation of model parameters. This can go as far as large parameter fields such as forcing fields that may drive or constrain a model. Future efficient data assimilation systems will probably incorporate these fields as part of control space. This overview of inverse modelling techniques describes regularization, information processing, Bayesian, and maximum entropy on the mean approaches, and estimation of the regularization parameters. Each concept introduced in this overview is illustrated using the concrete example of the inversion of the Chernobyl radionuclides source term with the help of a three-dimensional dispersion model.
Dynamically evolving networks
Authors: Grindrod CBE Peter
Published: March 2015

This chapter considers centrality measures for static and evolving networks of various different types. In particular it considers networks that evolve both discretely and continuously in time. In each case it shows how the notion of centrality may be extended to such situations so as to identify influential broadcasters and listeners. The chapter considers how this might relate to the fragility of networks and to problems of discounting old information and updating in real time. This exploits matrix algebra and matrix valued functions. Presented are examples of mobile phone social networks and corporate email networks.
Customer journeys and Markov chains
Authors: Grindrod CBE Peter
Published: March 2015

This chapter considers Markov models for customer behavioural change and hence customer value change based on longitudinal customer data. It considers the use of genetic algorithms in calibrating such models. It presents applications to a supermarket chain, mobile phone company, and to an online grocery.
The Large Hadron Collider
Authors: Evans Lyndon
Published: March 2015

This chapter discusses the design principles of the LHC, which gives access to the TeV energy scale for the first time. To achieve this, a number of technological innovations have been necessary. Two counter-rotating proton beams are guided and focused by superconducting magnets with a two-in-one structure allowing the machine to be installed in an existing tunnel. The very high field (>8 T) in the dipoles can only be achieved by cooling them below the superfluid transition temperature of liquid helium. More than 80 tons of superfluid helium is needed to cool the machine. In its first year of operation, the LHC has behaved very reliably and predictably. Single-bunch currents 30% above the design value have already been achieved, and the luminosity has increased by five orders of magnitude in the first 200 days of operation. Some of the results of commissioning and first operation are also discussed.
The LHC detectors and the first CMS data
Authors: Green Dan
Published: March 2015

This chapter describes the subsystems of a generic LHC detector and explains how the values of the detector parameters were selected. The design of the LHC detectors follows from the requirement of confronting electroweak symmetry breaking in a decisive fashion. The LHC accelerator also meets those requirements.
External Arguments in Transitivity Alternations
Authors: Alexiadou Artemis , Anagnostopoulou Elena , Schäfer Florian
Published: March 2015

This book is an exploration of the syntax of external arguments in transitivity alternations from a cross-linguistic perspective. The empirical focus is the causative/anticausative alternation and the formation of (adjectival) Passives. The bulk of the discussion, couched within Distributed Morphology, is devoted to the properties of the (anti-)causative alternation, which the text takes to be a Voice alternation. It offers a detailed discussion of the morphological realization of anticausatives across languages, and argues that marked anticausatives involve expletive Voice and are not reflexive predicates. In the discussion of Passives, the book argues that the fact that Passives in German and English—unlike their counterparts in Greek, where Passives are syncretic with anticausatives—are morphologically unique reflects the fact that they are also structurally unique. Passives in English and German involve Passive Voice, while they involve Middle Voice in Greek. The text furthermore shows that the distinction between target and resultant state participles is an important one in order to understand the contribution of Voice in adjectival Passives. Importantly, the study provided tools to probe into the morpho-syntactic structure of verbs and participles, and to identify the properties of verbal alternations across languages.
Event decomposition and the causative alternation
Authors: Alexiadou Artemis , Anagnostopoulou Elena , Schäfer Florian
Published: March 2015

This chapter provides evidence that while indeed anticausative predicates lack agentivity, they do involve a cause component. Importantly, causatives and anticausatives do not differ in terms of event complexity or event decomposition, but only in the absence vs. presence of the layer introducing the external argument, which is assumed to be VoiceP, following Kratzer (1996). It further discusses a number of diagnostics that can be used to identify the presence of a cause layer within anticausatives, and their cross-linguistic distribution. These include causer PPs and oblique causers, as well as the behavior of roll verbs across languages. The final section discusses in detail the question of how to determine which verbs alternate within a language and across languages.
Adjectival passives and Voice
Authors: Alexiadou Artemis , Anagnostopoulou Elena , Schäfer Florian
Published: March 2015

This chapter discusses adjectival passives and specifically the question of whether or not Voice is present. Looking into the properties of adjectival passives in general, and systematically in English, Greek, and German, is an integral part of the discussion, as these have been claimed to differ from verbal passives in lacking Voice. First, it is shown that German and English participles may contain Voice. Second, negated participles in English, German, and Greek will be argued to also provide evidence for the presence of Voice, a fact entailing that they cannot be treated as lexical and must be phrasal. And third, new data from Greek will lead to the conclusion that Greek target state participles may contain Voice, similarly to resultant state participles. The chapter shows that the distinction between target state and resultant state participles is instrumental in understanding the role of Voice in adjectival participles.
Conclusions
Authors: Alexiadou Artemis , Anagnostopoulou Elena , Schäfer Florian
Published: March 2015

This chapter summarizes our results. This study analyzes the properties of the (anti-)causative alternation, which is viewed as a Voice alternation. Anticausatives do not differ from causatives in event complexity, but only in that the latter contain a thematic Voice head, which the former lack. A further important proposal made is that there are three non-active heads involved in argument alternations: expletive, Middle, and Passive. This suggests that morphology provides us with an important tool to understand syncretism: from our perspective, Voice syncretisms (more particularly, syncretisms involving Voice heads) are expected to emerge in languages that make use of the Middle Voice head. It furthermore showed that the distinction between target state and resultant state participles is important in understanding the contribution of Voice. Importantly, the study provided tools to probe into the morpho-syntactic structure of verbs and participles, and to identify the properties of verbal alternations across languages.
Binding and crossover
Authors: Barker Chris , Shan Chung-Chieh
Published: March 2015

Chapter 2 develops the basic explanation for weak crossover. This involves a variable‐free approach to pronoun meaning, as well as a type‐shifter called BIND that enables a quantifier to bind a pronoun under appropriate circumstances. Unlike most accounts, there is no requirement that a quantifier must c‐command a pronoun in order to bind it; data is given arguing that this is a good result. A simple example of weak crossover is discussed, along with an explanation of how the tower fragment blocks binding in such examples. A variant combination rule is temporarily considered which reverses the order of the scope bias, and which simultaneously generates weak crossover examples. This demonstrates the role played by the left‐to‐right bias built into the combination schema in explaining the ungrammaticality of crossover.
Reconstruction effects
Authors: Barker Chris , Shan Chung-Chieh
Published: March 2015

Chapter 6 explains how the tower grammar handles reconstruction. Reconstruction examples show that a simple linear‐order constraint would not be adequate, since in reconstruction a quantifier can bind a pronoun that linearly precedes it. We show that, given the independently‐motivated account of wh‐fronting and relative clause formation in the previous chapter, reconstruction examples fall out without additional stipulation. Unlike accounts in which reconstruction involves syntactic movement, Principle C effects are not expected on the account developed here. The analysis is extended to reconstruction into relative clauses, as well as to examples involving idiom chunks, reflexives, and other anaphors. Crucially, even in reconstruction examples, crossover constraints remain in effect: roughly, a quantifier can only bind a pronoun if the quantifier precedes the reconstruction gap site.
Donkey anaphora and donkey crossover
Authors: Barker Chris , Shan Chung-Chieh
Published: March 2015

Chapter 9 develops an account of donkey anaphora on which the binding scope of an indefinite is a subdomain of its logical (LF) scope. This requires analyzing the conditional using split scope, in such a way that the conditional contributes an instance of negation that is able to take scope independently from the rest of the contribution of the conditional. This enables the indefinite to take scope over the antecedent and the consequent without taking scope over the detached negation. This leads to good predictions concerning the problem of indistinguishable participants (the bishop problem). It also leads to good predictions for conjoined and disjoined antecedents. Crucially, the continuation‐based evaluation order account correctly predicts donkey crossover: that the indefinite antecedent must be evaluated (processed) earlier than the donkey pronoun.
Strategies for determiners
Authors: Barker Chris , Shan Chung-Chieh
Published: March 2015

Chapter 10 extends the previous chapter’s approach to handle examples in which a donkey indefinite is embedded inside a DP, including classic cases of donkey anaphora in which the donkey antecedent is inside a relative clause. This requires constructing lexical entries for quantificational determiners that explicitly manage transmission of binding side effects from the nominal complement to the larger determiner phrase. Of particular interest is a scope roofing constraint that says that if a quantifier binds a pronoun that is inside a DP, the quantifier must take scope over the entire DP that contains the pronoun. Although questions remain about the implementation of various constraints on scope, no matter how those questions are resolved, donkey anaphora out of DP gives rise to robust crossover effects, as predicted by an evaluation‐order account.