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Early learning of a second language at home has been found to be beneficial for children’s cognitive development, including their ability to ascribe mental states to others. We investigated whether second language learning in an educational setting can accelerate children’s sensitivity to a communication partner’s perspective and whether the amount of exposure to second language education makes a difference. We tested three groups of English monolingual four-five year old children with varying language exposure at the beginning of their first year at primary school and 24 weeks later. Children attending bilingual schools and children with weekly second language lessons exhibited similar accelerated development of communicative perspective-taking skills compared to children without second language provision. Such advances were not related to other cognitive advances. Thus, limited foreign language teaching might boost young children’s development in communicative perspective-taking skills, providing an enhanced basis for their social competence development.
We show that March’s criterion for the existence of a bounded nonconstant harmonic function on a weak model (that is, $\mathbb {R}^n$ with a rotationally symmetric metric) is also a necessary and sufficient condition for the solvability of the Dirichlet problem at infinity on a family of metrics that generalise metrics with rotational symmetry on $\mathbb {R}^n$. When the Dirichlet problem at infinity is not solvable, we prove some quantitative estimates on how fast a nonconstant harmonic function must grow.
Data tax (DT) could re-establish states’ legitimacy by governing economic actors and promoting social solidarity and welfare through benefits. However, the overall impact of DT will depend on decisions about what social benefits DT funds (universal basic income or less expensive public goods) and whether benefits will entrench or challenge harmful business models and practices. Focusing on the right to science (RtS), the paper argues that DT could realise the RtS in the digital age through taxation that exacted not only data rent but also rent on the scientific heritage. Finally, the paper emphasises the need for international coordination to ensure that DT is equitably shared among developed and less developed countries.
Herbicide-resistant weeds threaten modern agriculture production. In Michigan, horseweed (Erigeron canadensis L.; syn. Conyza canadensis (L.) Cronq.) is among the most troublesome weeds, and glyphosate was widely used to control E. canadensis. Due to extreme selection pressure imposed by heavy glyphosate usage, glyphosate-resistant E. canadensis is widespread. New technologies to control resistant E. canadensis are being introduced in the form of multiple herbicide-resistance traits into glyphosate-resistant soybean (e.g. dicamba or 2,4-D choline). These new soybean [Glycine max (L.) Merr.] varieties will likely increase the use of 2,4-D and dicamba thus increasing the resistance selection pressure in E. canadensis. Predicting agronomic factors that drive herbicide-resistance evolution can serve as an effective proactive tool to advise practitioners to modify management strategies. Therefore, the objectives of this study are: 1) conduct dose-response assays to assess current resistance spectrum of E. canadensis collected in Michigan and 2) predict and determine the main factors in row crop production that contribute to resistance evolution in these accessions. Dose-response assays were conducted to evaluate the herbicide sensitivity spectrum to glyphosate, dicamba, and 2,4-D in 20 E. canadensis accessions collected from eight Michigan counties. Out of the 20 accessions, 60% were resistant to glyphosate, 35% to 2,4-D, and 20% to dicamba. Pearson’s correlation coefficient of dose-response values were positive in all comparisons (2,4-D-dicamba, r = 0.35; dicamba-glyphosate, r = 0.15; 2,4-D-glyphosate, r = 0.21). Dose-response data were integrated in odds ratio analyses to access the influence that previous management history had on the occurrence of resistance. Out of the significant pairwise comparisons, 44% were related to crop rotation frequency, 33% to previous herbicide-resistance status, and 22% to location collected. Results highlight that growers have the ability to proactively manage herbicide-resistance evolution progression of E. canadensis in Michigan by adopting integrated weed management techniques to slow successive selection events that occur in low diversity management systems.
Albeit laboratory experiments and numerical simulations have proven themselves successful in enhancing our understanding of long-living large-scale flow structures in horizontally extended Rayleigh–Bénard convection, some discrepancies with respect to their size and induced heat transfer remain. This study traces these discrepancies back to their origins. We start by generating a digital twin of one standard experimental set-up. This twin is subsequently simplified in steps to understand the effect of non-ideal thermal boundary conditions, and the experimental measurement procedure is mimicked using numerical data. Although this allows for explaining the increased observed size of the flow structures in the experiment relative to past numerical simulations, our data suggests that the vertical velocity magnitude has been underestimated in the experiments. A subsequent reassessment of the latter's original data reveals an incorrect calibration model. The reprocessed data show a relative increase in $u_{z}$ of roughly $24\,\%$, resolving the previously observed discrepancies. This digital twin of a laboratory experiment for thermal convection at Rayleigh numbers $Ra = \{ 2, 4, 7 \} \times 10^{5}$, a Prandtl number $Pr = 7.1$ and an aspect ratio $\varGamma = 25$ highlights the role of different thermal boundary conditions as well as a reliable calibration and measurement procedure.
The cosmological argument for the existence of God seems to have significant intuitive resonance. According to a familiar version of the cosmological argument, there must be some explanation for why the universe exists, and God provides the explanation. This argument seems to depend on the Principle of Sufficient Reason (PSR), according to which, if something exists, there must be an explanation for why it exists. As we detail, recent evidence indicates that people presuppose something like the PSR in their explanatory outlook. However, the other key part of the cosmological argument is that God is supposed to be self-explanatory – God’s existence is necessary. We examine this empirically and find that people do not generally think that the existence of God is necessary in the sense relevant for the cosmological argument.
Taking inspiration from the work of Douglass North, much institutional research attempts a distinction between ‘formal’ and ‘informal’ institutions. North often associated ‘formal institutions’ with rules enforced through a legal system. It is suggested here that this lead should be followed and refined. In which case ‘legal system’ and ‘law’ require definitions. An alternative claim, that ‘formal’ basically means ‘written down’, is arguably less useful. Stressing the importance of clear definitions in this area, this paper considers a case where slight modifications yield strikingly different results. Some options concerning the meanings of ‘culture’ and their relation to institutions are briefly noted. Changes in, and interactions between, ‘formal’ and ‘informal’ institutions are considered, with illustrative examples. Contrary to some authors, informal institutions can sometimes change rapidly, in some cases in response to state legislation.
In this paper, I explore how two recent politically charged deaths—those of George Floyd and Ashli Babbitt—illuminate the broader dynamics inherent in the concept of political martyrdom and its relationship to American democracy. Political martyrdom (as distinct from that associated with religious communities) offers martyrs a life beyond the grave, not by promising eternal life or paradise, but by ensuring them a role in a community’s collective memory. It involves three components: death, in what we might call “unnatural” circumstances, generally connected to an individual’s identity (or identities) or political commitments; consecration of that death, embedding it in a community’s collective memory and ascribing to it transcendent meaning; and transmission, the passing down of martyrdom narratives over time through media, ritual, and commemorative practices. The paper uses the examples of Floyd and Babbitt to illustrate the value of this conceptual category, one that focuses less on the personal qualities of individuals and more on communities’ narrations of their lives and deaths; highlights such narratives’ capacity to build collective identities over time, often in contexts far removed from the martyrs’ own lives and deaths; and offers new interpretive lenses for considering twenty-first-century issues of systemic violence and structural injustice.
We present PCFTL (Probabilistic CounterFactual Temporal Logic), a new probabilistic temporal logic for the verification of Markov Decision Processes (MDP). PCFTL introduces operators for causal inference, allowing us to express interventional and counterfactual queries. Given a path formula φ, an interventional property is concerned with the satisfaction probability of φ if we apply a particular change I to the MDP (e.g., switching to a different policy); a counterfactual formula allows us to compute, given an observed MDP path τ, what the outcome of φ would have been had we applied I in the past and under the same random factors that led to observing τ. Our approach represents a departure from existing probabilistic temporal logics that do not support such counterfactual reasoning. From a syntactic viewpoint, we introduce a counterfactual operator that subsumes both interventional and counterfactual probabilities as well as the traditional probabilistic operator. This makes our logic strictly more expressive than PCTL⋆. The semantics of PCFTL rely on a structural causal model translation of the MDP, which provides a representation amenable to counterfactual inference. We evaluate PCFTL in the context of safe reinforcement learning using a benchmark of grid-world models.
The genus Rhinebothrium (Cestoda: Rhinebothriidea) comprises tapeworm species parasitizing elasmobranch hosts, particularly batoids. Despite numerous recent findings regarding the ecological importance of marine fish parasites throughout the world, the biodiversity of cestodes inhabiting fishes of the Persian Gulf and the Gulf of Oman remains understudied. Here, two new species of Rhinebothrium from stingrays from the Persian Gulf and Gulf of Oman are described: Rhinebothrium gossi sp. nov. and Rhinebothrium palmeri sp. nov. from Maculabatis arabica and Maculabatis randalli, respectively. However, each new cestode species is found with a lower frequency in the other host species, too. These new species were already subjected to a molecular analysis and the revealed genetic distinctiveness requires detailed morphological examinations at the species level. A combination of morphomeristic characteristics including body size, scolex features, proglottid morphology, and reproductive structures distinguish the new species from the other congeners. Although these new species are morphologically similar, however, they differ from each other in the number of testes (6–8 and 8–14), and bothridial loculi (50 and 42 in R. gossi sp. nov. and R. palmeri sp. nov., respectively). These findings contribute to our understanding of marine cestode diversity and underscore the importance of further research in this ecologically significant region.
We solve ‘half’ the problem of finding three-dimensional quasisymmetric magnetic fields that do not necessarily satisfy magnetohydrostatic force balance. This involves determining which hidden symmetries are admissible as quasisymmetries, and then showing explicitly how to construct quasisymmetric magnetic fields given an admissible symmetry. The admissibility conditions take the form of a system of overdetermined nonlinear partial differential equations involving second derivatives of the symmetry's infinitesimal generator.
Iconicity facilitates learning signs, but it is unknown whether recognition of meaning from the sign form occurs automatically. We recorded ERPs to highly iconic (transparent) and non-iconic ASL signs presented to one group who knew they would be taught signs (learners) and another group with no such expectations (non-learners). Participants watched sign videos and detected an occasional grooming gesture (no semantic processing required). Before sign onset, learners showed a greater frontal negativity compared to non-learners for both sign types, possibly due to greater motivation to attend to signs. During the N400 window, learners showed greater negativity to iconic than non-iconic signs, indicating more semantic processing for iconic signs. The non-learners showed a later and much weaker iconicity effect. The groups did not differ in task performance or in P3 amplitude. We conclude that comprehending the form-meaning mapping of highly iconic signs is not automatic and requires motivation and attention.
Established hedgerows of native plants on the borders of crop fields provide a variety of ecosystem service benefits in agricultural landscapes. However, their influence on weed communities is not well understood, and there are concerns that hedgerows could contribute to weed infestations on farms. To address this research gap, we examined the role of established hedgerows of native California plants on weed abundance (weed numbers and cover) and weed species richness in field borders and in adjacent crops, in large-scale, monocropping systems compared with conventionally managed field borders (i.e., no hedgerows). Across 20 farm sites in California’s Central Valley, hedgerows on orchard crop borders reduced weed numbers by 66%, weed species richness by 59%, and weed cover by 74%. On annual field crop borders, hedgerows reduced weed numbers by 71%, weed species richness by 60%, and weed cover by 70%. In orchards, hedgerows also reduced weed intrusion into the adjacent crop interior, with significantly lower weed cover to the first tree row (area directly underneath the trees), weed species richness to the 10 m tree row, and weed numbers to the 10 m avenue (area between the tree rows). Yearly management practices and associated costs for weed control in established hedgerows were significantly less than for conventionally managed field borders. This study highlights the effectiveness of native hedgerows as a sustainable nature-based solution for reducing weed pressure and management inputs on farms.
Imagine that you are given access to an AI chatbot that compellingly mimics the personality and speech of a deceased loved one. If you start having regular interactions with this “thanabot,” could this new relationship be a continuation of the relationship you had with your loved one? And could a relationship with a thanabot preserve or replicate the value of a close human relationship? To the first question, we argue that a relationship with a thanabot cannot be a true continuation of your relationship with a deceased loved one, though it might support one’s continuing bonds with the dead. To the second question, we argue that, in and of themselves, relationships with thanabots cannot benefit us as much as rewarding and healthy intimate relationships with other humans, though we explain why it is difficult to make reliable comparative generalizations about the instrumental value of these relationships.