Chimera States and Seizures in a Mouse Neuronal Model

Chimera states - the coexistence of synchrony and asynchrony in a nonlocally-coupled network of identical oscillators - are often used as a model framework for epileptic seizures. Here, we explore the dynamics of chimera states in a network of modified Hindmarsh-Rose neurons, configured to reflect the graph of the mesoscale mouse connectome. Our model produces superficially epileptiform activity converging on persistent chimera states in a large region of a two-parameter space governing connections (a) between subcortices within a cortex and (b) between cortices. Our findings contribute to a growing body of literature suggesting mathematical models can qualitatively reproduce epileptic seizure dynamics

Cosmological constraints from clustering properties of galaxy clusters

In this paper, we discuss improvements of the Suto et al. (2000) model, in the light of recent theoretical developments (new theoretical mass functions, a more accurate mass-temperature relation and an improved bias model) to predict the clustering properties of galaxy clusters and to obtain constraints on cosmological parameters. We re-derive the two-point correlation function of clusters of galaxies for OCDM and LambdaCDM cosmological models, and we compare these results with the observed spatial correlation function for clusters in RASS1 (ROSAT All-Sky Survey 1), and in XBACs (X-RAY Brighest Abell-Type) samples. The comparison shows that the best agreement is obtained for the LambdaCDM model with Omega=0.3. The values of the correlation length obtained, (r_\simeq 28.2 \pm 5.2 \rm h^{-1}} Mpc for LambdaCDM), are larger than those found in the literature and comparable with the results found in Borgani, Plionis & Kolokotronis (1999). (REST IN THE PAPER ABSTRACT)Comment: printed in A&

Predicting global habitat suitability for stony corals on seamounts

Aim Globally, species distribution patterns in the deep sea are poorly resolved, with spatial coverage being sparse for most taxa and true absence data missing. Increasing human impacts on deep-sea ecosystems mean that reaching a better understanding of such patterns is becoming more urgent. Cold-water stony corals (Order Scleractinia) form structurally complex habitats (dense thickets or reefs) that can support a diversity of other associated fauna. Despite their widely accepted ecological importance, records of scleractinian corals on seamounts are patchy and simply not available for most of the global ocean. The objective of this paper is to model the global distribution of suitable habitat for stony corals on seamounts. Location Seamounts worldwide. Methods We compiled a database containing all accessible records of scleractinian corals on seamounts. Two modelling approaches developed for presence-only data were used to predict global habitat suitability for seamount scleractinians: maximum entropy modelling (Maxent) and environmental niche factor analysis (ENFA). We generated habitat-suitability maps and used a cross-validation process with a threshold-independent metric to evaluate the performance of the models. Results Both models performed well in cross-validation, although the Maxent method consistently outperformed ENFA. Highly suitable habitat for seamount stony corals was predicted to occur at most modelled depths in the North Atlantic, and in a circumglobal strip in the Southern Hemisphere between 20° and 50° S and shallower than around 1500 m. Seamount summits in most other regions appeared much less likely to provide suitable habitat, except for small near-surface patches. The patterns of habitat suitability largely reflect current biogeographical knowledge. Environmental variables positively associated with high predicted habitat suitability included the aragonite saturation state, and oxygen saturation and concentration. By contrast, low levels of dissolved inorganic carbon, nitrate, phosphate and silicate were associated with high predicted suitability. High correlation among variables made assessing individual drivers difficult. Main conclusions Our models predict environmental conditions likely to play a role in determining large-scale scleractinian coral distributions on seamounts, and provide a baseline scenario on a global scale. These results present a first-order hypothesis that can be tested by further sampling. Given the high vulnerability of cold-water corals to human impacts, such predictions are crucial tools in developing worldwide conservation and management strategies for seamount ecosystems. © 2009 Blackwell Publishing Ltd

The Arctic and the UK: Climate, research and engagement

• The Arctic has warmed by around 2°C since 1850, approximately double the global average. Even if the Paris Agreement successfully limits global warming to a further 0.5°C, the Arctic is expected to warm by at least another 1°C. • The United Kingdom’s (UK) weather is linked to conditions in the European Arctic. For example, high atmospheric pressure in the Nordic Seas divert damaging storms across the UK and mainland Europe, with the potential to cause societal disruption from flooding. • It is possible, although presently unconfirmed, that alterations in Arctic conditions provoked the ‘Beast from the East’ winter storm in 2018. • Scientists need to take observations and improve their understanding of climatic processes in the Nordic Seas and the Arctic Ocean to fill gaps in knowledge about the links between the Arctic climate and the UK’s weather; a risk identified by the Intergovernmental Panel on Climate Change (IPCC). • The UK has significant research expertise and experience to understand how global warming will change the Arctic’s environment and affect the UK. • This strength, allied with the capabilities of the UK’s new polar research ship the RRS Sir David Attenborough, warrants an integrated programme of research, including advanced numerical modelling, to improve predictions of future extreme weather events. • Such a programme must acknowledge that the Arctic is politically an increasingly congested and contested space. It should be designed in collaboration with key Arctic and near-Arctic nations to increase the UK’s influence and abilit

Pennsylvania Folklife Vol. 19, No. 4

• Whittling: Dumb Dutch Pastime • Amish Plain Costume: A Matter of Choice • It\u27s Sticky - But We Love It • The Folk Festival Seminars: Folk Art and Antique Collecting • Festival Highlights • Folk Festival Program • 19th-Century Ballooning Tradition Continues at Kutztown Festival • Jump-Rope Rhymes • Ghost Stories and Old Superstitions of Lancaster County • Mary Goes Over the Mountain • Children\u27s Games: Folk-Cultural Questionnaire No. 16https://digitalcommons.ursinus.edu/pafolklifemag/1040/thumbnail.jp

Spatial Scales of Bacterial Diversity in Cold-Water Coral Reef Ecosystems

Background: Cold-water coral reef ecosystems are recognized as biodiversity hotspots in the deep sea, but insights into their associated bacterial communities are still limited. Deciphering principle patterns of bacterial community variation over multiple spatial scales may however prove critical for a better understanding of factors contributing to cold-water coral reef stability and functioning. Methodology/Principal Findings: Bacterial community structure, as determined by Automated Ribosomal Intergenic Spacer Analysis (ARISA), was investigated with respect to (i) microbial habitat type and (ii) coral species and color, as well as the three spatial components (iii) geomorphologic reef zoning, (iv) reef boundary, and (v) reef location. Communities revealed fundamental differences between coral-generated (branch surface, mucus) and ambient microbial habitats (seawater, sediments). This habitat specificity appeared pivotal for determining bacterial community shifts over all other study levels investigated. Coral-derived surfaces showed species-specific patterns, differing significantly between Lophelia pertusa and Madrepora oculata, but not between L. pertusa color types. Within the reef center, no community distinction corresponded to geomorphologic reef zoning for both coral-generated and ambient microbial habitats. Beyond the reef center, however, bacterial communities varied considerably from local to regional scales, with marked shifts toward the reef periphery as well as between different in- and offshore reef sites, suggesting significant biogeographic imprinting but wea

Assessing the living and dead proportions of cold-water coral colonies: implications for deep-water Marine Protected Area monitoring in a changing ocean

Coral growth patterns result from an interplay of coral biology and environmental conditions. In this study colony size and proportion of live and dead skeletons in the cold-water coral (CWC) Lophelia pertusa (Linnaeus, 1758) were measured using video footage from Remotely Operated Vehicle (ROV) transects conducted at the inshore Mingulay Reef Complex (MRC) and at the offshore PISCES site (Rockall Bank) in the NE Atlantic. The main goal of this paper was to explore the development of a simple method to quantify coral growth and its potential application as an assessment tool of the health of these remote habitats. Eighteen colonies were selected and whole colony and dead/living layer size were measured. Live to dead layer ratios for each colony were then determined and analysed. The age of each colony was estimated using previously published data. Our paper shows that: (1) two distinct morphotypes can be described: at the MRC, colonies displayed a ‘cauliflower-shaped’ morphotype whereas at the PISCES site, colonies presented a more flattened ‘bush-shaped’ morphotype; (2) living layer size was positively correlated with whole colony size; (3) live to dead layer ratio was negatively correlated to whole colony size; (4) live to dead layer ratio never exceeded 0.27. These results suggest that as a colony develops and its growth rate slows down, the proportion of living polyps in the colony decreases. Furthermore, at least 73% of L. pertusa colonies are composed of exposed dead coral skeleton, vulnerable to ocean acidification and the associated shallowing of the aragonite saturation horizon, with significant implications for future deep-sea reef framework integrity. The clear visual contrast between white/pale living and grey/dark dead portions of the colonies also gives a new way by which they can be visually monitored over time. The increased use of marine autonomous survey vehicles offers an important new platform from which such a surveying technique could be applied to monitor deep-water marine protected areas in the futureVersión del edito

The dispositionalist deity: how God creates laws and why theists should care

How does God govern the world? For many theists “laws of nature” play a vital role. But what are these laws, metaphysically speaking? I shall argue that laws of nature are not external to the objects they govern, but instead should be thought of as reducible to internal features of properties. Recent work in metaphysics and philosophy of science has revived a dispositionalist conception of nature, according to which nature is not passive, but active and dynamic. Disposition theorists see particulars as being internally powerful rather than being governed by external laws of nature, making external laws in effect ontologically otiose. I will argue that theists should prefer a dispositionalist ontology, since it leads them toward the theory of concurrentism in divine conservation, rather than occasionalism, and revives the distinction between internal and external teleology. God on this view does not govern the world through external laws of nature, but rather through internal aspects of powerful properties

Scaling up: material culture as scaffold for the social brain

Many other species besides Homo sapiens are tool-users and even tool-makers, but one aspect of material culture still sets modern humans apart: our emotional and social engagement with objects. Here I argue that this engagement acted as a crucial scaffold for the scaling-up of human social networks beyond those of our closest relatives the chimpanzees to the global ‘small world’ of modern humans. Material culture plays a crucial role in conveying social information about relationships between people, places and things that extend geographically and temporally beyond the here and now – a role which allowed our ancestors to off-load some of the cognitive demands of maintaining such extensive social networks, and thereby surpass the limits to sociality imposed by neurology alone. Broad-scale developments in the archaeological record of the Lower Palaeolithic through to the early Neolithic are used to trace the process by which hominins and humans slowly scaled up their social worlds