Small carbonaceous fossils (SCFs) from the Terreneuvian (lower Cambrian) of Baltica

We describe a new assemblage of small carbonaceous fossils (SCFs) from diagenetically 9 minimally altered clays and siltstones of Terreneuvian age from the Lontova and Voosi formations of 10 Estonia, Lithuania and Russia. This is the first detailed account of an SCF assemblage from the 11 Terreneuvian, and includes a number of previously undocumented Cambrian organisms. Recognisably 12 bilaterian-derived SCFs include abundant protoconodonts (total-group Chaetognatha), and distinctive 13 cuticular spines of scalidophoran worms. Alongside these metazoan remains are a range of protistan-14 grade fossils, including Retiranus balticus gen. et sp. nov., a distinctive funnel-shaped or sheet-like 15 problematicum characterized by terminal or marginal vesicles, and Lontohystrichosphaera grandis 16 gen. et sp. nov., a large (100–550 μm) ornamented vesicular microfossil. Together these data offer a 17 fundamentally enriched view of Terreneuvian life in the epicratonic seas of Baltica, from an episode 18 where records of non-biomineralized life are currently sparse. Even so, the recovered assemblages 19 contain a lower diversity of metazoans than SCF biotas from younger (Stage 4) Baltic successions that 20 represent broadly equivalent environments, echoing the diversification signal recorded in the coeval 21 shelly and trace-fossil records. Close comparison to the biostratigraphic signal from Fortunian small 22 shelly fossils (SSFs) supports a late Fortunian age for most of the Lontova/Voosi succession, rather 23 than a younger (wholly Stage 2) range.NER

Small carbonaceous fossils (SCFs) from the Terreneuvian (lower Cambrian) of Baltica

We describe a new assemblage of small carbonaceous fossils (SCFs) from diagenetically 9 minimally altered clays and siltstones of Terreneuvian age from the Lontova and Voosi formations of 10 Estonia, Lithuania and Russia. This is the first detailed account of an SCF assemblage from the 11 Terreneuvian, and includes a number of previously undocumented Cambrian organisms. Recognisably 12 bilaterian-derived SCFs include abundant protoconodonts (total-group Chaetognatha), and distinctive 13 cuticular spines of scalidophoran worms. Alongside these metazoan remains are a range of protistan-14 grade fossils, including Retiranus balticus gen. et sp. nov., a distinctive funnel-shaped or sheet-like 15 problematicum characterized by terminal or marginal vesicles, and Lontohystrichosphaera grandis 16 gen. et sp. nov., a large (100–550 μm) ornamented vesicular microfossil. Together these data offer a 17 fundamentally enriched view of Terreneuvian life in the epicratonic seas of Baltica, from an episode 18 where records of non-biomineralized life are currently sparse. Even so, the recovered assemblages 19 contain a lower diversity of metazoans than SCF biotas from younger (Stage 4) Baltic successions that 20 represent broadly equivalent environments, echoing the diversification signal recorded in the coeval 21 shelly and trace-fossil records. Close comparison to the biostratigraphic signal from Fortunian small 22 shelly fossils (SSFs) supports a late Fortunian age for most of the Lontova/Voosi succession, rather 23 than a younger (wholly Stage 2) range.NER

Oxygen minimum zones in the early Cambrian ocean

The relationship between the evolution of early animal 26 communities and oceanic oxygen levels remains unclear. In particular, uncertainty persists in reconstructions of redox conditions during the pivotal early Cambrian (541-510 million years ago, Ma), where conflicting datasets from deeper marine settings suggest either ocean anoxia or fully oxygenated conditions. By coupling geochemical palaeoredox proxies with a record of organic-walled fossils from exceptionally well-defined successions of the early Cambrian Baltic Basin, we provide evidence for the early establishment of modern-type oxygen minimum zones (OMZs). Both inner- and outer shelf environments were pervasively oxygenated, whereas mid-depth settings were characterized by spatially oscillating anoxia. As such, conflicting redox signatures recovered from individual sites most likely derive from sampling bias, whereby anoxic conditions represent mid-shelf environments with higher productivity. This picture of a spatially restricted anoxic wedge contrasts with prevailing models of globally stratified oceans, offering a more nuanced and realistic account of the Proterozoic-Phanerozoic ocean transition

Evolutionary synchrony of Earth's biosphere and sedimentary-stratigraphic record

The landscapes and seascapes of Earth’s surface provide the theatre for life, but to what extent did the actors build the stage? The role of life in the long-term shaping of the planetary surface needs to be understood to ascertain whether Earth is singular among known rocky planets, and to frame predictions of future changes to the biosphere. Modern geomorphic observations and modelling have made strides in this respect, but an under-utilized lens through which to interrogate these questions resides in the most complete tangible record of our planetary history: the sedimentary-stratigraphic record (SSR). The characteristics of the SSR have been frequently explained with reference to changes in boundary conditions such as relative sea level, climate, and tectonics. Yet despite the fact that the long-term accrual of the SSR was contemporaneous with the evolution of almost all domains of life on Earth, causal explanations related to biological activity have often been overlooked, particularly within siliciclastic strata. This paper explores evidence for the ways in which organisms have influenced the SSR throughout Earth history and emphasizes that further investigation can help lead us towards a mechanistic understanding of how the planetary surface has co-evolved with life. The practicality of discerning life signatures in the SSR is discussed by: 1) distinguishing biologically-dependent versus biologically-influenced sedimentary signatures; 2) emphasizing the importance of determining relative time-length scales of processes and demonstrating how different focal lengths of observation (individual geological outcrops and the complete SSR) can reveal different insights; and 3) promoting an awareness of issues of equifinality and underdetermination that may hinder the recognition of life signatures. Multiple instances of life signatures and their historic range within the SSR are reviewed, with examples covering siliciclastic, biogenic and chemogenic strata, and trigger organisms from across the spectrum of Earth’s extant and ancient life. With this novel perspective, the SSR is recognised as a dynamic archive that expands and complements the fossil and geochemical records that it hosts, rather than simply being a passive repository for them. The SSR is shown to be both the record and the result of long-term evolutionary synchrony between life and planetary surface processes

Big-Data-Driven Materials Science and its FAIR Data Infrastructure

This chapter addresses the forth paradigm of materials research -- big-data driven materials science. Its concepts and state-of-the-art are described, and its challenges and chances are discussed. For furthering the field, Open Data and an all-embracing sharing, an efficient data infrastructure, and the rich ecosystem of computer codes used in the community are of critical importance. For shaping this forth paradigm and contributing to the development or discovery of improved and novel materials, data must be what is now called FAIR -- Findable, Accessible, Interoperable and Re-purposable/Re-usable. This sets the stage for advances of methods from artificial intelligence that operate on large data sets to find trends and patterns that cannot be obtained from individual calculations and not even directly from high-throughput studies. Recent progress is reviewed and demonstrated, and the chapter is concluded by a forward-looking perspective, addressing important not yet solved challenges.Comment: submitted to the Handbook of Materials Modeling (eds. S. Yip and W. Andreoni), Springer 2018/201

Geometric morphometrics of macro- and meiofaunal priapulid pharyngeal teeth provides a proxy for studying Cambrian “tooth taxa”

Priapulids are marine, benthic ecdysozoan worms that feed using a distinctive toothed pharynx. While only a handful of lineages have survived to the present day, the Cambrian priapulid stem group left behind a rich record of articulated body fossils and characteristic trace fossils in the form of burrows. Recently, the fossil record of isolated priapulid cuticular elements including pharyngeal teeth has gained increased attention as a means of revealing cryptic priapulid taxa otherwise unknown among macrofossils. In this study, we focus on the ecological implications of shape variation in the teeth of extant and extinct priapulids, which display substantial morphological differences between taxa and life stages. We define a landmarking scheme to capture shape variation in priapulid teeth and apply it to our dataset, which includes a breadth of tooth specimens from extant macrofaunal and meiofaunal lineages alongside numerous Cambrian priapulid teeth preserved as isolated small carbonaceous fossils. Through ordination of the principal components of shape, we explore the priapulid tooth morphospace and find evidence that its occupancy has expanded since Cambrian times, indicating a corresponding expansion of the group’s ecological niche. We also employ our geometric morphometric approach to make linear discriminant analysis-based taxon assignments based on tooth morphology, which can be helpful for classifying enigmatic “tooth taxa” known solely from fossil teeth. Finally, we use discriminant analysis to study tooth shapes from a functional perspective, considering known ecologies to characterize the ecological functions of unclassified isolated teeth

Mott physics and band topology in materials with strong spin-orbit interaction

Recent theory and experiment have revealed that strong spin-orbit coupling can have dramatic qualitative effects on the band structure of weakly interacting solids. Indeed, it leads to a distinct phase of matter, the topological band insulator. In this paper, we consider the combined effects of spin-orbit coupling and strong electron correlation, and show that the former has both quantitative and qualitative effects upon the correlation-driven Mott transition. As a specific example we take Ir-based pyrochlores, where the subsystem of Ir 5d electrons is known to undergo a Mott transition. At weak electron-electron interaction, we predict that Ir electrons are in a metallic phase at weak spin-orbit interaction, and in a topological band insulator phase at strong spin-orbit interaction. Very generally, we show that with increasing strength of the electron-electron interaction, the effective spin-orbit coupling is enhanced, increasing the domain of the topological band insulator. Furthermore, in our model, we argue that with increasing interactions, the topological band insulator is transformed into a "topological Mott insulator" phase, which is characterized by gapless surface spin-only excitations. The full phase diagram also includes a narrow region of gapless Mott insulator with a spinon Fermi surface, and a magnetically ordered state at still larger electron-electron interaction.Comment: 10+ pages including 3+ pages of Supplementary Informatio

Talk to the Virtual Hands: Self-Animated Avatars Improve Communication in Head-Mounted Display Virtual Environments

Background When we talk to one another face-to-face, body gestures accompany our speech. Motion tracking technology enables us to include body gestures in avatar-mediated communication, by mapping one's movements onto one's own 3D avatar in real time, so the avatar is self-animated. We conducted two experiments to investigate (a) whether head-mounted display virtual reality is useful for researching the influence of body gestures in communication; and (b) whether body gestures are used to help in communicating the meaning of a word. Participants worked in pairs and played a communication game, where one person had to describe the meanings of words to the other. Principal Findings In experiment 1, participants used significantly more hand gestures and successfully described significantly more words when nonverbal communication was available to both participants (i.e. both describing and guessing avatars were self-animated, compared with both avatars in a static neutral pose). Participants ‘passed’ (gave up describing) significantly more words when they were talking to a static avatar (no nonverbal feedback available). In experiment 2, participants' performance was significantly worse when they were talking to an avatar with a prerecorded listening animation, compared with an avatar animated by their partners' real movements. In both experiments participants used significantly more hand gestures when they played the game in the real world. Conclusions Taken together, the studies show how (a) virtual reality can be used to systematically study the influence of body gestures; (b) it is important that nonverbal communication is bidirectional (real nonverbal feedback in addition to nonverbal communication from the describing participant); and (c) there are differences in the amount of body gestures that participants use with and without the head-mounted display, and we discuss possible explanations for this and ideas for future investigation

Does preoperative weight loss in a specialist medical weight management centre influence postoperative weight loss after bariatric surgery?

Summary: Weight loss of 5%–10% is advised in medical weight management (MWM) programmes prior to bariatric surgery but it remains to be established whether it influences postoperative weight loss outcomes. We studied postoperative percent total weight loss (%TWL) in 168 patients categorized by preoperative referral weight loss <5% or ≥5% in a UK NHS bariatric centre. Eighty‐six (51.2%) patients achieved sustained referral weight loss <5% (Group A) and 82 (48.8%) ≥5% (Group B). Overall postoperative %TWL in Group A compared with Group B was 30.0% versus 28.3% (p = .30) at 12 months and 32.5% versus 29.6% (p = .20) at 24 months. There were no significant differences in postoperative %TWL at 12 and 24 months when categorized by procedure (gastric bypass, n = 106; or sleeve gastrectomy, n = 62), age or sex. Preoperative weight loss during intensive specialist MWM did not influence postoperative weight loss up to 24 months with gastric bypass or sleeve gastrectomy