Island Configurations Research Articles

Category-Sensitive Escape from Islands in Limbum and Asante Twi

While strong islands generally constitute domains from which extraction is not possible, it has been observed that under certain conditions, they may allow DP but not PP gaps. Based on the recent literature on Asante Twi (Kwa, Ghana) and on novel data from Limbum (Grassfields Bantu, Cameroon), this paper shows that strong island configurations in these two African languages are permeable to nominal extractees without restrictions, but the otherwise admissible movement of VPs and PPs is blocked. As DP-displacement from islands shows properties of A¯-movement; an explanation in terms of base-generation and binding of a covert resumptive pronoun, which is only available for nominal elements, is not feasible. Taking into account the overall distribution of overt and covert resumptive pronouns, for Asante Twi, an account of the selective island permeability in terms of repair by resumption, as suggested in previous literature, might be possible. For the Limbum pattern, however, this paper argues that such an approach seems implausible. It then goes on to develop an analysis of selective island permeability based on the distribution of ϕ-features and their interaction with complementizer agreement.

Fast ion confinement in the presence of core magnetic islands in Wendelstein 7-X

The effect of magnetic islands in the core region of Wendelstein 7-X (W7-X) on fast ion confinement is explored through simulations with the BEAMS3D code. A magnetic configuration where the n/m=5/5 island chain is shifted to r/a∼0.7 allows the exploration of core island physics in W7-X. The control coil system on W7-X allows the tuning of the island size either increasing the island width or decreasing it. A coupling of the BEAMS3D code to the FIELDLINES code provides a versatile mechanism for incorporating magnetic islands and stochastic regions into the BEAMS3D code. Collisionless simulations suggest that the presence of core islands degrade the confinement of passing particles in the region of the island chain. Full neutral beam simulations of W7-X show a similar behavior with confinement decreasing as the island width is increased. Comparisons between a vacuum magnetic field and low beta HINT2 simulation are made showing similar fast ion behavior. Measurements of lost fast ions in W7-X confirm this trend with the control coil suppressed island configuration showing lower losses than that with no control coils applied. Simulations of fast ion wall loads are performed suggesting no drastic change in loss pattern and a slight reduction in losses with minimized islands.

MEDIS—A comprehensive spatial database on Mediterranean islands for biogeographical and evolutionary research

AbstractMotivationThe intrinsic characteristics of islands make them a unique study system for the investigation of ecological and evolutionary dynamics. The Mediterranean Basin, an island‐rich biodiversity hotspot, still lacks a comprehensive spatial database for these geographic features. This study presents the first comprehensive spatial database of all Mediterranean islands larger than 0.01 km2, aiding ecological investigations and interdisciplinary research.Main types of variable containedThe MEDIS spatial database offers detailed information on 39 geographic, climatic, ecological and land‐use variables, including island area, perimeter, isolation metrics, climatic space, terrain data, land cover, palaeogeography, road networks and geological information, providing a multifaceted view of each island's characteristics.Spatial location and grainThe study encompasses 2217 islands in the Mediterranean Basin larger than 0.01 km2. The spatial grain of the datasets on which the selected variables are based varies from 10 m (ESA WorldCover) to 1 km (CHELSA‐BIOCLIM+).Time period and grainThe spatial database incorporates data from various sources, each with its own timeframe, such as the Global Shoreline Vector from 2014 Landsat imagery and the WorldCover dataset from 2021. Historical data like the Paleocoastlines GIS dataset offer insights into island configurations during the Last Glacial Maximum.Major taxa and level of measurementWhile not focusing on specific taxa, the study lays the foundation for comprehensive research on Mediterranean islands, facilitating comparisons and investigations into the distribution of native, endemic or alien species. The level of measurement is extensive, encompassing a wide range of variables and providing polygonal features rather than centroids' coordinates.

The Absence of Islands in Akan: The Role of Resumption

The precise nature of Ā-dependencies that terminate in a pronoun has been a long-standing subject of cross-linguistic research. Traditionally, it has been assumed that there are two derivational strategies to form resumptive Ā-dependencies: movement and base generation. Island configurations have played a crucial role in determining which derivational strategy is employed in a given language, as islands effects are expected to arise from dependencies created by movement but not by base generation. The body of cross-linguistic research on resumption has shown that the situation is more complicated once other diagnostics are taken into account, as languages can have mixed resumption profiles. In this paper, we discuss resumption in Ā-dependencies in Akan, a Kwa language spoken in Ghana, and illustrate that, despite their general insensitivity to islands, resumptive dependencies also show many classic hallmarks of movement. We situate these findings in the broader context of a general understanding of resumption cross-linguistically and discuss how the conflicting diagnostics might be reconciled with a movement-based analysis.

Absence of Clausal Islands in Shupamem

Decades-long research on islands has led to the conclusion that island constraints are candidates for language universals. A recent surge in research on islandhood in African languages has revealed some would-be island configurations that are transparent for A¯- dependency formation. In this article, we show that in Shupamem, all clausal configurations expected to have the status of opaque island domains fail to block the formation of long-distance A¯- dependencies involving object ex situ focus. In support of the claim that A¯- movement has occurred in such cases, we rely on evidence from three wh- movement diagnostics (weak crossover effects, reconstruction phenomena and quantifier float). Furthermore, we show that non-movement dependencies across purported island boundaries in the language are also possible through the licensing of “island”-internal negative concord items by external non-local negators. We conclude that clausal island effects fail to materialize in Shupamem ex situ focus constructions and negative concord item-licensing domains. Based on an exploratory typological survey of islands in African languages, we indicate a trend toward varying degrees of island permeability in the area, concluding that while Shupamem is not an isolated example, it features one of the most permissive grammars known to date in this respect.

The Role of D-Linking and Lexical Restriction in Locality Violations

The major contrast discussed in the literature to show an obviation of the wh-island effect often involves a bare wh- element in the role of the intervener (e.g. who) and a “complex” wh-phrase (e.g. which book) in the role of the moved item. This contrast is not minimal, since it is not sufficient to disentangle the role of D-linking (Pesetsky 1987) from that of the so-called “lexical restriction” (Friedmann, Belletti, and Rizzi 2009). In this work we try to fill this gap by contrasting, in an argumental wh- island configuration (e.g. “… [who read …]”), which NP vs. what NP both in English and in Italian (e.g. which/what book and quale/che libro). We argue that while both wh- phrases can be genuinely considered “lexically restricted”, the first, and not the second, has properties that make it allegedly D-linked (i.e. a canonical partitive interpretation is available). Our acceptability studies show that (in both languages) no significant difference is revealed in the scores attributed to the two extracted wh-phrases and no significant variance (e.g. indicating a binomial distribution) is observed in the condition what NP. The first result indicates that the “D-linking” hypothesis as an independent source of amelioration is inadequate; the second result suggests that also the hypothesis that the condition what/che NP might be ambiguous between a D-linked and a non-D-linked reading is unlikely.

Effect of Twin Island Configuration on Airwake Aerodynamics over Generic Aircraft Carrier using CFD

The technological advancements have led to the evolution of numerous concepts in an aircraft carrier’s topdeck design, the twin island concept being the latest entrant. An aircraft carrier’s bluff body geometry presents many challenges to the pilot, landing on deck being the most critical. The present study aims to undertake a computational investigation of the aerodynamic analysis of a Twin Island GAC (Generic Aircraft Carrier) conceptualized vis- à-vis its base variant. The flow over the twin island GAC flight deck and downstream is analysed using various transverse planes perpendicular to the flow direction as detailed in the paper. Subsequently, a parametric study was undertaken for understanding the effects of longitudinal translations of the two islands with respect to the baseline GAC position. The results depict the advantage of certain variants of twin islands over a single island, and ~68 % reduction in turbulence is achieved along the glideslope by one of the variations which could aid in reducing pilot workload. The data can act as a catalyst for utilization and incorporation in future floating platform designs and further studies in this field.

Phylogenomic and population genomic analyses reveal the spatial–temporal dynamics of diversification of the Nigella arvensis complex (Ranunculaceae) in the Aegean archipelago

The continental-shelf islands of the Aegean Sea provide an ideal geographical setting for evolutionary-biogeographical studies but disentangling the relationships between palaeogeographical history and the times, orders of modes of taxon divergence is not straightforward. Here, we used phylogenomic and population genomic approaches, based on orthologous gene sequences and transcriptome-derived SNP data, to reconstruct the spatial–temporal evolution of the Aegean Nigella arvensis complex (Ranunculaceae; 11 out of 12 taxa). The group’s early diversification in the Early/Mid-Pliocene (c. 3.77 Mya) resulted in three main lineages (Greek mainland vs. central Aegean + Turkish mainland/eastern Aegean islands), while all extant taxa are of Late Plio-/Early Pleistocene origin (c. 3.30–1.59 Mya). Demographic modelling of the outcrossing taxa uncovered disparate modes of (sub)speciation, including divergence with gene flow on the Greek mainland, para- or peripatric diversification across eastern Aegean islands, and a ‘mixing–isolation–mixing (MIM)’ mode of subspeciation in the Cyclades. The two selfing species (N. stricta, N. doerfleri) evolved independently from the outcrossers. Present-day island configurations are clearly insufficient to explain the spatial–temporal history of lineage diversification and modes of (sub)speciation in Aegean Nigella. Moreover, our identification of positively selected genes in almost all taxa calls into question that this plant group represents a case of ‘non-adaptive’ radiation. Our study revealed an episodic diversification history of the N. arvensis complex, giving new insight into the modes and drivers of island speciation and adaption across multiple spatiotemporal scales.

Compactified extra dimension and entanglement island as clues to quantum gravity

We show that the compactified extra dimension and the emergence of the island can provide clues about quantum gravity because their combination can solve the deepest puzzles of black hole physics. Suppose that the time dimension and the extra dimension compactified on a circle are symmetric under double Wick rotation, the curvature singularity would be removed due to the end of spacetime as a smooth bubble hidden behind the event horizon. The smooth bubble geometries can also be interpreted as microstates leading to the Bekenstein–Hawking entropy because the smooth bubble geometries live in the same region of mass and charge as the black string. In addition, by applying the quantum extremal surface prescription, we show the emergence of the island at late times of the black string evaporation where it is located slightly outside the event horizon. Due to the dominant contribution of the island configuration, the entanglement entropy of the radiation grows no longer linearly in time but it reaches a finite value that is twice the Bekenstein–Hawking entropy at the leading order. This transition shows the information preservation during the black string evaporation. Furthermore, we calculate the Page time which determines the moment of the transition between the linearly growing and constant behaviors of the entanglement entropy as well as the scrambling time corresponding to the information recovery time of the signal falling into the black string.

Control Design of Grid-Forming and Grid-Following Inverters with a seamless transition in Microgrid

The development of renewable energy resources has grown significantly in recent years. These distributed energy resources are typically connected to the grid through power converters, which can be operated in "grid-forming" or "grid-following" mode. But the large-scale integration of DG units has serious repercussions on the stability of the power system due to their low inertia compared to the synchronous generator. However, an appropriate control guarantees a dynamic, smooth, and fast converter behaviour in an island configuration and voltage-frequency support in grid-connected mode. This paper presents a control system for Grid-Following and Grid-Following converters for a grid-connected MG. The aim is to achieve a seamless transition between the Microgrid and the main grid, appropriate load sharing between distributed energy sources, and an improvement of system stability. The developed grid-connected battery storage system inverter has been designed to be able to operate in two different modes: grid formation mode and grid injection mode. The control strategy considers the control loops of Voltage/current, Frequency, and active/reactive power. The proposed control technique is presented and simulated under the MATLAB/Simulink tool. The simulation results demonstrate the efficiency and performance of the proposed control technique in eliminating voltage, current, and frequency fluctuations and also guarantee a seamless transition between the two modes.

A note on islands in Schwarzschild black holes

We consider evaporation of the Schwarzschild black hole and note that island configurations do not provide a bounded entanglement entropy. The same remark is also valid for some other static black holes. A proposal for improving the situation is discussed.

The role of resumption in the acquisition of European Portuguese prepositional relative clauses by Chinese learners

This article reports on an experimental study on the acquisition of prepositional relative clauses in second language European Portuguese by Chinese native speakers. It focuses on the role of resumption, mandatory in prepositional relative clauses in Chinese (the native language of the learners) and non-conventional in European Portuguese (the target language). Results of an oral production task and two online acceptability judgment tasks indicated that resumption does not transfer from the native language, and that Chinese learners of European Portuguese employ movement structures to produce and process relative clauses. Additionally, results showed that resumptive pronouns do not rescue or ameliorate ungrammatical extractions from islands, contrary to what is traditionally assumed in grammatical theory. This finding was kept constant across participants, native and non-native. Overall, we conclude that second language speakers are able to select and reassemble movement features in their non-native language and use similar processing mechanisms as native speakers to analyse island configurations.

Planar black holes in holographic axion gravity: Islands, Page times, and scrambling times

The present work investigates the entanglement entropies of the Hawking radiations, the Page times, and the scrambling times, for the eternal planar black holes in the holographic axion gravity. The solutions correspond to a new class of charged black holes, because the boundary diffeomorphism is broken due to the graviton mass induced by the axion fields in the bulk. The information theoretical aspects of these black hole solutions is determined upon applying the island rule for the entanglement entropy. Like non-extremal charged black holes, the radiation entropy grows linearly in the no-island configurations, while is saturated at late times by asymptotic values set by the Bekenstein-Hawking entropy in the island configurations, with the boundary being located slightly outside the outer horizon. In particular, for the extremal black planes of holographic axion gravity, we find that: (a) the entanglement entropy of the Hawking radiation is ill-defined at the early times when the island is absent; (b) it tends to a distinctive constant at the late times; (c) the late-time location of the island is indeed universal. Moreover, we investigate how the Page time is affected by the holographic massive gravity deformation. For neutral solutions at the small deformation parameter, and for charged solutions with almost-extremal deformation parameter, we find that the Page transition happens at earlier times.

Numerical modelling of hydraulic efficiency and pollution transport in waste stabilization ponds

This paper investigates the hydraulic performance and solute transport processes in waste stabilization ponds (WSPs). A numerical model comprised of Reynolds-averaged Navier–Stokes (RANS) flow hydrodynamic model with the standard k − ε turbulence closure coupled with the advection-diffusion solute transport model, is developed in a three-dimensional Cartesian coordinate system. The proposed numerical model is successfully validated against laboratory-scale physical modelling measurements of flow hydrodynamics and solute characteristics across trapezoidal pond geometry. The developed numerical model is adopted to run series of scenario-based simulations to investigate the effects of WSP's geometrical features and implementation of an island retrofitting on the hydraulic performance and treatment efficiency of the WSPs. Fifteen pond configurations with varying side-walls slope and island configurations are simulated. Vertical and horizontal structures of flow hydrodynamics across the pond are investigated. Solute transport processes are studied through determining residence time distribution (RTDs) curves based on numerical tracer simulations. Two deflector island configurations (parallel and rotated) are simulated to investigate their influence on enhancing the hydraulic performance of the WSP. The analysis of the numerical results indicates an overall positive impact of deflector island retrofitting on the hydraulic performance of the WSP. The side-walls slope are shown to play a key role in determining the overall performance of the WSP. For the cases with side-walls slope of 1:1, 0.5:1 and 0:1, the hydraulic efficiency of the WSP was enhanced by adding both parallel and rotated islands. However, for the cases with side-walls slope of 2:1 and 1.5:1, addition of island deflector is shown to have negative impacts on the hydraulic performance of the waste stabilization pond.

The universality of islands outside the horizon

We systematically calculate the quantum extremal surface (QES) associated with Hawking radiation for general D-dimensional (D ≥ 2) asymptotically flat (or AdS) eternal black holes using the island formula. We collect the Hawking radiation particles by a non-gravitational bath and find that a QES exists in the near-horizon region outside the black hole when c · G(D) is smaller enough where c is the central charge of the conformal matter and G(D) the D-dimensional Newton constant. The locations of the QES in these backgrounds are obtained and the late-time radiation entropy saturates the two times of black hole entropy. Finally, we numerically check that the no island configuration exists once c · G(D) exceeds a certain upper bound in two-dimensional generalized dilaton theories (GDT). When c · G(D) close to the upper bound, the backreaction of the matter field on the background can not be neglected. We also consider the conditions of existence of the island configuration with the backreaction and prove that the upper bound also exist for the Witten black hole and Weyl-related Witten black hole.

Frugivore distributions are associated with plant dispersal syndrome diversity in the Caribbean archipelagos

AbstractAimMany plants rely on interactions with frugivores for dispersal, suggesting that animal communities may affect plant occupancy and diversity. However, the contribution of these interaction‐led biotic variables on plant diversity is poorly understood, especially in archipelagic hotspots such as the Caribbean. In island ecosystems, biogeographic theories suggest that island configurations drive colonization‐extinction dynamics, while macroecology argues for the importance of climatic drivers of biodiversity. Within this context, we examine how frugivore‐driven biotic factors are associated with fruiting plant species richness in relation to abiotic (climatic and geologic) and island configuration characteristics.LocationCaribbean archipelagos.MethodsWe compiled a review of the diversity and distributions of 6039 plants and 326 vertebrate frugivores across 105 islands within the Caribbean. We then identified characteristics related to plant‐frugivore interactions and assigned each species as having either abiotic (wind, water, etc.) or zoochoric (frugivory‐dependent) dispersal syndromes. We related plant richness and dispersal syndromes to the regional diversity and characteristics of frugivorous animals, abiotic environments and island configuration characteristics through stepwise multivariate regression with generalized linear models and model selection.ResultsWe found that 44.6% of Caribbean plants are dispersed through frugivory (endozoochory). Frugivore‐related characteristics, namely accumulated body mass of island bird assemblages, were the best predictors of the diversity of seed dispersal syndromes. To a lesser degree, reptile richness and soil variety were also considered important predictors for zoochoric plant distribution, while island areas affected abiotically‐dispersed plants.Main conclusionWe found that biotic characteristics of frugivore communities are important predictors of plant diversity in the Caribbean archipelagos. However, this may also be influenced by climate and colonization history. Given the importance of biotic metrics in explaining plant diversity, we suggest that fruit‐frugivore interactions are important components of island biogeography and that frugivorous communities should be accounted for plant biodiversity predictions and forecast models.

The real-time status of strong and weak islands.

In two eye-tracking reading experiments, we used a variant of the filled gap technique to investigate how strong and weak islands are processed on a moment-to-moment basis during comprehension. Experiment 1 provided a conceptual replication of previous studies showing that real time processing is sensitive to strong islands. In the absence of an island, readers experienced processing difficulty when a pronoun appeared in a position of a predicted gap, but this difficulty was absent when the pronoun appeared inside a strong island. Experiment 2 showed an analogous effect for weak islands: a processing cost was seen for a pronoun in the position of a predicted gap in a that-complement clause, but this cost was absent in a matched whether clause, which constitutes a weak island configuration. Overall, our results are compatible with the claim that active dependency formation is suspended, or reduced, in both weak and strong island structures.

Islands in Kaluza\u2013Klein black holes

The newly proposed island formula for entanglement entropy of Hawking radiation is applied to spherically symmetric 4-dimensional eternal Kaluza–Klein (KK) black holes. The “charge” Q of KK black holes quantifies its deviation from Schwarzschild black holes. The impact of Q on the island is studied at late times. The late-time island, whose boundary is located outside but within a Planckian distance of the horizon, is slightly extended by Q. While the no-island entropy grows linearly, the late-time entanglement entropy is given by island configuration with twice the Bekenstein–Hawking entropy. Thus we reproduce the Page curve for the eternal KK black holes. Compared with Schwarzschild results, the Page time is delayed by a factor (1+Q/r_h) and the scrambling time is prolonged by a factor (1+Q/r_h)^{1/2}. Moreover, the higher-dimensional generalization is presented. Skeptically, there are Planck length scales involved, in which a semi-classical description may break down.

Bird diversity on shelf islands does not benefit from recent land‐bridge connections

AbstractAimResearch in island biogeography has long focused mainly on present‐day island configurations. Recently, there has been an increasing focus on islands’ past histories of land connection, shape and size. Moreover, continental islands (=shelf islands) have received less attention than oceanic islands, and species inventories from extremely small islands are lacking in many datasets. We examine the effects of sea‐level rise since the Last Glacial Maximum (LGM) on bird species diversity and composition of tropical shelf islands in Southeast Asia.LocationSundaland.TaxonBirds.MethodsWe compiled avifaunal island inventories for 94 islands using an exhaustive literature review of historic surveys of larger islands combined with our own comprehensive island surveys from both small and large islands. Using generalised least‐squares models with spatial autocorrelation, we assessed the importance of traditional biogeographical parameters including area, maximum elevation, distance from mainland and geographical isolation, along with post‐LGM effects of change in island area and duration since isolation. We also compared the species composition on similar‐sized shelf islands from two categories—recently submerged and unsubmerged—using non‐metric multidimensional scaling.ResultsPost‐LGM effects on species diversity are minimal and insular diversity is instead well explained by present‐day island characteristics, such as area, distance to mainland and proportion of land surrounding an island within a 10 km radius (Cox and Snell Pseudo‐R2 = 0.803). Avifaunal diversity is similar across recently submerged and unsubmerged small shelf islands.Main conclusionAvifaunal diversity on tropical shelf islands equilibrates rapidly after isolation, indicating that both extinction and immigration rates are high. In particular, a high immigration rate of dispersive species maintains diversity, especially on small islands. Over‐water dispersal is generally restricted to short distances among Sundaic birds. Consequently, the diversity of an island can be maintained by the presence of large or stepping‐stone islands near it.

Impact of organic inter-layer dielectric for improvement in mechanical flexibility of self-aligned coplanar in-Ga-Zn-O thin-film transistor

A novel device structure has been suggested to introduce organic inter-layer dielectric (ILD) for improving mechanical flexibility of self-aligned (SA) coplanar In-Ga-Zn-O (IGZO) thin-film transistor (TFT). The SA coplanar TFTs fabricated on poly(ethylene naphthalate) (PEN) substrate showed a high saturation mobility of 11.4 cm 2 /V∙s, low threshold voltage of 0.26 V, steep subthreshold swing of 115 mV/dec, and high on/off current ratio (~10 9 ) at flat state. In the proposed structure, all-oxide gate stacks were defined into an island configuration embedded in the organic ILD, and hence, the mechanical stress applied to the active region could be effectively relieved. To investigate the feasibility of a new device concept, the mechanical properties of the fabricated TFTs were characterized. When the PEN thickness was varied 25 and 50 μm, the critical radius of curvature (R C ) values were estimated to be 1 and 3 mm, respectively, which were superior to those for conventional oxide devices. In addition, the mechanical durability during the cyclic bending test at R C of 5 mm was significantly improved from 20,000 to 70,000 cycles when the PEN film thickness was reduced from 50 to 25 μm. The effects of PEN thickness on the mechanical stability of the SA coplanar TFTs were quantitatively discussed from a view point of surface strain. As a result, robust mechanical bendability of proposed device was confirmed even under harsh deformation conditions. • We fabricated flexible SA coplanar IGZO TFTs employing Zeocoat™ ILD on PEN film. • Effects of the island configuration on mechanical flexibility were investigated. • The device structure using organic ILD is favorable design for stress relaxation. • The PEN film thickness has marked impacts on strain induced on device plane. • Reduction of PEN thickness is effective for enhancing the mechanical durability.