bluuebunny/crossref_metadata_2025 huggingface dataset:
Defining Big Data
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter looks at the definition of ‘Big Data’. It focuses on personal data, which is generally defined as ‘any information relating to an identified or identifiable individual (data subject)’. The Organisation for Economic Co-operation and Development (OECD) provides a list of types of personal data which the chapter discusses. These are: user-generated, including blogs and commentary, photos, and videos, etc; activity or behavioural data, including what people search for and look at on the Internet, what people buy online, how much and how they pay, etc; social data, including contacts and friends on social networking sites; locational data, including residential addresses, GPS, and geo-location, IP address, etc; demographic data, including age, gender, race, income, sexual preferences, political affiliation, etc; and identifying data of an official nature, including name, financial information and account numbers, health information, national health or social security numbers, police records, etc.
Smartphones as an Example of How Big Data and Privacy Intersect
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter analyses smartphones in discussing how Big Data is quantitatively and qualitatively different from the data collected before. In particular, it looks at the case of Riley v California and the unanimous decision here issued by the US Supreme Court. The case mainly stems from the issue of whether the government could search a suspect’s smartphone without a warrant. The Fourth Amendment of the US Constitution prohibits unreasonable searches and seizures, and requires the government to first obtain a warrant, supported by probable cause. There are several expanding exceptions for warrantless searches and seizures. In the end, the Supreme Court decided that searching a smartphone is not the same as searching someone’s wallet or purse. The case reveals that although Fourth Amendment Constitutional issues may seem far afield from competition policy, it raises interesting privacy issues.
Why Haven’t Market Forces Addressed Consumers’ Privacy Concerns?
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter explores the reasons why market forces are not promoting services that protect consumer privacy. One possible explanation is that consumers—especially younger ones—are not concerned about privacy. But survey data refutes this claim. A second possible explanation is that competition, at times, can worsen, rather than improve, the privacy protections. But that still leaves markets where competitive market forces should be responsive to consumers’ demand for better privacy protections, but are not. The fundamental problem in these markets is that consumers lack viable alternatives. It is in here where the core concern of competition policy—namely the accumulation of market power—intersects with privacy concerns. The main reason why market forces have not yielded the privacy protections that consumers want/demand is the absence of meaningful competition.
The US’s and EU’s Mixed Record in Assessing Data-Driven Mergers
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter examines the recent track record of EU and US competition authorities in assessing data-driven mergers to determine whether, and to what extent, competition agencies’ analysis has improved. The assessment of several recent investigations reveals how some agencies—notably the European Commission and US Department of Justice—are at least starting to engage with or address the issue of Big Data. However, there are still missing key issues. The chapter discusses these issues by describing and analysing six recent data-driven mergers and the response of competition authorities: TomTom/TeleAtlas, Facebook/WhatsApp, Alliance Data Systems Corp/Conversant, Google/Nest Labs and Google/Dropcam, Google/Waze, and the Bazaarvoice/PowerReviews merger. These data-driven mergers highlight the enforcers’ hits and misses in understanding the implications of Big Data.
Agencies Focus on What is Measurable (Price), Which is Not Always Important (Free Goods)
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter examines how price effects have predominated antitrust analysis in the US. Competition agencies have never disclaimed the importance of non-price competition. Indeed, the consensus is that the effects of mergers or restraints on dynamic efficiencies, including innovation, are often more important than the effect on short-term prices. Nonetheless, economic factors that were easier to measure, such as the merger’s likely short-term impact on price, output, or productive efficiency in narrowly defined markets, became disproportionately important. Factors that were harder to assess or measure like the merger’s impact on innovation, systemic risk, and the risks that the increasing concentration of power pose to democracy and individual autonomy were ignored or discounted. The competition authorities specifically recognize the importance of quality competition. In assessing whether a merger may substantially lessen quality or other parameters of non-price competition, competition agencies employ an approach analogous to that used to evaluate price competition.
Data-Driven Mergers Often Fall Outside Competition Policy’s Conventional Categories
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

One reason why competition agencies have not fully considered the implications of Big Data is that data-driven mergers can defy or challenge the agencies’ conventions that work well for other mergers. This chapter explores three conventions: the categorization of mergers, the belief that similar products/services compete more fiercely than dissimilar products/services, and the focus on the substitutability of services or products. It also examines how competition agencies categorize mergers as horizontal, vertical, and/or conglomerate. Regardless of the category, the ultimate assessment is the same, namely whether the merger may substantially reduce competition or create a monopoly (or monopsony). But the analytical framework differs depending on whether it is a horizontal, vertical, or conglomerate merger.
Importance of Entry Barriers in Antitrust Analysis
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter describes the importance of entry barriers in antitrust analysis. A key issue is whether entry barriers are sufficiently low to alleviate concerns about adverse competitive effects. Some argue that data does not lend itself to entry barriers. The Organisation for Economic Co-operation and Development (OECD), for example, noted three trends underlying data-driven innovation: the exponential growth in data generated and collected; the widespread use of data analytics including by start-ups and small and medium enterprises (SMEs); and the emergence of a paradigm shift in knowledge creation and decision-making. Others, however, claim that online markets are notable for their low entry barriers and typically do not require big data for entry. The merging parties or dominant firm may use the traditional factors that the agencies consider to argue that entry barriers are generally low in that online industry.
Entry Barriers Can Be Higher in Multi-Sided Markets, Where One Side Exhibits Traditional Network Effects
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter examines traditional network effects in the Facebook/WhatsApp merger to assess how entry barriers can be higher in multi-sided markets, where one side exhibits traditional network effects. Despite the absence of traditional entry barriers due to their online nature, the Facebook/WhatsApp merger raised the traditional direct network effects with which enforcers and courts are most comfortable. The merger involved classic direct network effects in two different product markets: texting apps and social networking. Recognizing how the texting apps could be susceptible to these direct network effects, the European Commission did not end its analysis on the ‘traditional’ entry barriers. The value of a texting app, the European Commission found, increases as more and more people use that particular app. Thus, Facebook and WhatsApp both enjoy traditional network effects, whereby one’s utility from the product increases as others use the product.
Scale of Data
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter explores a second network effect, which arises from the scale of data: the more people who actively or passively contribute data, the more the company can improve the quality of its product, the more attractive the product is to other users. The chapter considers this data-driven network effect in three contexts: Waze’s navigation app, search engines, and Facebook’s digital assistant ‘M’. It argues that one can benefit (and one’s utility can increase) when others use the same search engine, since the quality of the search results can increase. As more people use the search engine, the more trial-and-error experiments, the more likely the search engine’s algorithms can learn of consumer preferences, the more relevant the search results will likely be, which in turn will attract others to use the search engine, and the positive feedback continues.
Two More Network Effects
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter analyses two more network effects: the scope of data and spill-over effects. It shows how the feedback loop is accelerated when the company harnesses the variety of data across its platform to improve the quality of its product, which attracts more users who provide the company with more data to further improve. These effects are examined through Facebook’s digital assistant ‘M’ and search engines. Through the scope of data effect, the more users rely on the platform’s other services, the greater the variety of personal data on particular users, the better the digital assistant can segment results by user profiles, and the better the digital assistant can personalize results. On the other hand, under spill-over effects, the growth of users on one side of the multi-sided platform can attract more advertisers or suppliers on the other side of the platform, which in turn attracts more users, advertisers, and suppliers.
Reflections on Data-Driven Network Effects
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter addresses several competition issues raised by data-driven network effects as they tend to be difficult to enter and are easily susceptible by one or two firms. The data-driven network effects in online markets can amplify the stakes of gaining and losing users. Depending on the network effect, the loss of users can degrade the product’s quality and reduce the likelihood of attracting (and retaining) users, advertisers, or sellers. With each user the platform acquires relative to its competitors, a quality gap emerges. If the quality differences become apparent to users, the feedback loop can accelerate—attracting both new users and users of the competitors’ products. Another issue raised is the localization of data-driven network effect in some markets. Regarding search engines, companies may be unable to fully leverage the network effects across languages; users likely want the search results in their own language.
Risk of Inadequate Merger Enforcement
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter identifies four significant risks in the ways competition agencies have analysed data-driven mergers, and how they have not fully considered the implications of a data-driven economy. First, it is questionable whether competition agencies are accurately predicting the competitive effects of mergers in concentrated markets. The second risk is when competition agencies consider only the merger’s impact on the ‘paid’ side of multi-sided platforms and ignore the free side. To illustrate, the chapter uses the wave of US commercial radio station mergers from the 1990s to the 2000s, where the Department of Justice considered in its consent decrees only the mergers’ effect on advertising, and not on listenership. The third risk is that, even if the agency reviews the merger’s likely effect on each side of the multi-sided platform, its price-centric tools are ill suited for evaluating the free side. The network effects can magnify the likely consumer harm—the fourth risk.
The Price of Weak Antitrust Enforcement
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter explains why the societal harm is too great to ignore data-driven mergers and abuses by dominant firms. The costs are high when agencies and courts get it wrong, going to the heart of many democratic systems. Anticompetitive data-driven mergers and monopolistic abuses can affect not only consumers’ economic interests but also their privacy interests and the values that underlie these privacy interests, such as individual autonomy and freedom of expression and association. Many of these industries, given the data-driven network effects, are ripe for consolidation. Thus, the incentives for mergers and exclusionary behaviour increase to tip the market towards dominance. Additionally, the chapter explains why privacy and consumer protection agencies and laws will not necessarily prevent these harms through behavioural remedies and fines.
Data-opoly: Identifying Data-Driven Exclusionary and Predatory Conduct
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter explores the issue of path dependence and competitive portals—critical inflection points where antitrust can make a key difference by focusing on data-driven anticompetitive exclusionary and predatory behaviour. Competition law can deter exclusionary and predatory practices and keep competitive portals. Big Data enhances this as it can confer power and a durable competitive advantage. This works in hand with data-driven network effects which improve product or service quality. At times, consumers benefit from this competitive rivalry and drive to maintain a data advantage. Companies innovate to expand their platform of services to secure a greater following. But when the stakes are greater, so too are the incentives to engage in unfair practices to tip the market to the company’s favour and maintain a monopoly. Consequently, competition authorities must be alert to dominant companies’ unfair practices aimed at thwarting competitors and disrupting innovators. The chapter outlines several potentially anticompetitive data-driven tactics.
Need for Retrospectives of Data-Driven Mergers
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This chapter discusses the benefits of conducting merger retrospectives. It highlights the risk of false negatives under the current quantification paradigm. One benefit is that the competition authority can evaluate its or the courts’ assumptions and analytical tools. Although the anticompetitive effects could be caused by unforeseen intervening events, the agency and court typically assess mergers through their price-centric models, which rely on several assumptions, such as the likely reaction of rational, self-interested consumers with willpower to a small, but significant, non-transitory price increase. The behavioural economic scholarship has drawn into question these assumptions of rationality and willpower. Thus, the merger retrospectives will reveal what happened to price and non-price competition and the extent to which actual marketplace behaviour comports with the predicted behaviour of rational agents with willpower.
Conclusion
Authors: Stucke Maurice E , Grunes Allen P
Published: August 2024

This concluding chapter describes the integral role of competition law in ensuring that everyone can realize the benefits of a data-driven economy while mitigating its associated risks. Policymakers must not assume that privacy, consumer protection, and competition policy concerns are so distinct that they should be left to their respective agencies. Likewise, the fact that privacy is a fundamental right in some jurisdictions does not mean that it is always relevant in competition policy. The chapter argues that people cannot afford a widening gap between enforcement and policy among jurisdictions. Such a gap leaves enforcers ill-equipped to identify and address the anticompetitive risks and privacy harms from data-driven mergers and abuses by dominant firms, subjects companies to inconsistent enforcement, and leaves consumers and start-ups vulnerable.
Income and campus application disparities among European and non-European heritage Hispanic undergraduate applicants
Authors: Alvero AJ , Giebel Sonia , Pearman Francis A
Published: August 2024

Leveraging every undergraduate application submitted by self-identified Hispanic applicants to the University of California system in the 2016 and 2017 application cycles, we show that a significant number of applicants claim Hispanic identity by virtue of European heritage. We subsequently demonstrate that Hispanic-identifying students of European descent are significantly more affluent and more likely to apply to selective University of California campuses than their non-European Hispanic peers. We comment on the practical implications of these disparities, as well as their relevance for studies of inequality in the social sciences and education.
Bio-molecular analyses enable new insights into the taphonomy of feathers
Authors: Pan Yanhong , Qi Zeming , Hu Jianfang , Zheng Xiaoting , Wang Xiaoli
Published: August 2024

Exceptionally preserved feathers from the Mesozoic era have provided valuable insights into the early evolution of feathers and enabled color reconstruction of extinct dinosaurs, including early birds. Mounting chemical evidence for the two key components of feathers—keratins and melanins—in fossil feathers has demonstrated that exceptional preservation can be traced down to the molecular level. However, the chemical changes that keratin and eumelanin undergo during fossilization are still not fully understood, introducing uncertainty in the identification of these two molecules in fossil feathers. To address this issue, we need to examine their taphonomic process. In this study, we analyzed the structural and chemical composition of fossil feathers from the Jehol Biota and compared them with the structural and chemical changes observed in modern feathers during the process of biodegradation and thermal degradation, as well as the structural and chemical characteristics of a Cenozoic fossil feather. Our results suggest that the taphonomic process of feathers from the Cretaceous Jehol Biota is mainly controlled by the process of thermal degradation. The Cretaceous fossil feathers studied exhibited minimal keratin preservation but retained strong melanin signals, attributed to melanin's higher thermal stability. Low-maturity carbonaceous fossils can indeed preserve biosignals, especially signals from molecules with high resistance to thermal degradation. These findings provide clues about the preservation potential of keratin and melanin, and serve as a reference for searching for those two biomolecules in different geological periods and environments.
China's progress in synergetic governance of climate change and multiple environmental issues
Authors: Yang Jianxun , Zhao Zhan , Fang Wen , Ma Zongwei , Liu Miaomiao , Bi Jun
Published: August 2024

Advancing the synergetic control of climate change and environmental crisis is crucial for achieving global sustainable development goals. This study evaluates synergetic governance levels over climate change and four environmental issues at the provincial level in China from 2009 to 2020. Our findings reveal significant progress in China's coordinated efforts to mitigate carbon emissions, reduce air pollutants, and conserve water resources. However, there remains room for improvement in managing solid waste and protecting ecological systems and overall progress in synergetic governance has slowed since 2015. Employing a random forest model, we identify socio-economic factors with great influence on synergetic climate change and environmental governance, such as energy intensity, service sector development, electronic equipment manufacturing, and transportation. Additionally, we reveal nonlinear relationships between some factors and performance of environmental subsystems, including both plateau effects (e.g. output in the smelting of ferrous metals) and U-shaped patterns (e.g. output in the manufacturing of metal products), possibly attributed to constraints in end-of-pipe treatment capacities and complexities in supply chain networks. Furthermore, through hierarchical clustering analysis, we classify provinces into four groups and provide tailored recommendations for policymakers to enhance synergetic governance levels in their respective regions. The framework established in this study also serves as a valuable reference for countries seeking to develop practical and context-specific solutions to mitigate climate and environmental risks.
Maximized response by structural optimization of soft elastic composite systems
Authors: Fischer Lukas , Menzel Andreas M
Published: August 2024

Soft actuators triggered in a wire—and contactless way advance soft robotics, for instance, concerning microsurgical perspectives. For optimal performance in this and other contexts, maximized stimuli-responsiveness is frequently desirable. We demonstrate on the example of soft magnetoelastic systems how analytical theoretical measures in combination with computer simulations provide tools to develop optimized components. To enhance the overall macroscopic response, we adjust microstructural properties. Our strategy guides us towards ideally structured soft materials that can be fabricated using modern technologies.
Identification and mechanism of wheat protein disulfide isomerase-promoted gluten network formation
Authors: Gao Jihui , Ma Jiayin , Yu Peixuan , Yang Dong
Published: August 2024

Formation of the gluten network depends on glutenin crosslinking via disulfide bonds, and wheat protein disulfide isomerase (wPDI) plays an important role in this process. Here, we identify a substrate gluten protein of wPDI and the mechanism underlying wPDI-promoted glutenin crosslinking. Farinographic, rheologic, and alveographic analysis unambiguously proves that wPDI improves gluten network formation, which is directly observed by 3D reconstruction of the gluten network. Protein analysis and LC–MS/MS reveal that glutenin subunit 1Dx5 is primarily recruited by wPDI to participate in gluten network formation, and its cysteine-containing N-terminal domain (1Dx5-NTD), which harbors three cysteine residues for crosslinking, is purified. 1Dx5-NTD interacts with wPDI in both redox states, possibly folded by reduced wPDI and then catalyzed by oxidized wPDI, as further evidenced by wPDI-promoted self-crosslinking. Consistent with macroscopic observations, our results suggest that wPDI folds 1Dx5-NTD into β-strand structure that favors disulfide bond formation.
Food and Food Security in the US Security Strategy (1987–2022)
Authors: Clementi Marco
Published: August 2024

This article underlines that food security is a relevant dimension of contemporary international instability and aims to clarify the role it has played in the strategic discourse of the United States, given the country is the main food donor in the world besides being significantly involved in international crises. To this aim, the article carries a qualitative and quantitative content analysis of the nineteen National Security Strategies published between 1987 and 2022. The research compares the way the different US Administrations have theorized food security and their respective elements of continuity and discontinuity. The research results show that food security is a steadily relevant issue in US strategic discourse, although the reasons for this strategic relevance change significantly with the political color of the Administration.
Effects of ECM protein-coated surfaces on the generation of retinal pigment epithelium cells differentiated from human pluripotent stem cells
Authors: Tian Zeyu , Liu Qian , Lin Hui-Yu , Zhu Yu-Ru , Ling Ling , Sung Tzu-Cheng , Wang Ting , Li Wanqi , Gao Min , Cheng Sitian , Renuka Remya Rajan , Subbiah Suresh Kumar , Fan Guoping , Wu Gwo-Jang , Higuchi Akon
Published: August 2024

Retinal degeneration diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP), initially manifest as dysfunction or death of the retinal pigment epithelium (RPE). Subretinal transplantation of human pluripotent stem cell (hPSC)-derived RPE cells has emerged as a potential therapy for retinal degeneration. However, RPE cells differentiated from hPSCs using current protocols are xeno-containing and are rarely applied in clinical trials. The development of hPSC-derived RPE cell differentiation protocols using xeno-free biomaterials is urgently needed for clinical applications. In this study, two protocols (the activin A and NIC84 protocols) were selected for modification and use in the differentiation of hiPSCs into RPE cells; the chetomin concentration was gradually increased to achieve high differentiation efficiency of RPE cells. The xeno-free extracellular matrix (ECM) proteins, laminin-511, laminin-521 and recombinant vitronectin, were selected as plate-coating substrates, and a Matrigel (xeno-containing ECM)-coated surface was used as a positive control. Healthy, mature hPSC-derived RPE cells were transplanted into 21-day-old Royal College of Surgeons (RCS) rats, a model of retinal degeneration disease. The visual function of RCS rats was evaluated by optomotor response (qOMR) and electroretinography after transplantation of hPSC-derived RPE cells. Our study demonstrated that hPSCs can be efficiently differentiated into RPE cells on LN521-coated dishes using the NIC84 protocol, and that subretinal transplantation of the cell suspensions can delay the progression of vision loss in RCS rats.
Tracking politically motivated reasoning in the brain: the role of mentalizing, value-encoding, and error detection networks
Authors: Lois Giannis , Tsakas Elias , Yuen Kenneth , Riedl Arno
Published: August 2024

Susceptibility to misinformation and belief polarization often reflects people’s tendency to incorporate information in a biased way. Despite the presence of competing theoretical models, the underlying neurocognitive mechanisms of motivated reasoning remain elusive as previous empirical work did not properly track the belief formation process. To address this problem, we employed a design that identifies motivated reasoning as directional deviations from a Bayesian benchmark of unbiased belief updating. We asked the members of a proimmigration or an anti-immigration group regarding the extent to which they endorse factual messages on foreign criminality, a polarizing political topic. Both groups exhibited a desirability bias by overendorsing attitude-consistent messages and underendorsing attitude-discrepant messages and an identity bias by overendorsing messages from in-group members and underendorsing messages from out-group members. In both groups, neural responses to the messages predicted subsequent expression of desirability and identity biases, suggesting a common neural basis of motivated reasoning across ideologically opposing groups. Specifically, brain regions implicated in encoding value, error detection, and mentalizing tracked the degree of desirability bias. Less extensive activation in the mentalizing network tracked the degree of identity bias. These findings illustrate the distinct neurocognitive architecture of desirability and identity biases and inform existing cognitive models of politically motivated reasoning.
Allergy, infarction, and stress cardiomyopathy: in-depth analysis of a complex clinical case report
Authors: Cacciapuoti Fulvio , Capone Valentina , Golino Paolo , Pezzullo Enrica , Bossone Eduardo , Cacciapuoti Federico
Published: August 2024

Background

Diagnosis of Kounis syndrome, an acute coronary syndrome associated with anaphylactic reactions, is challenging owing to the overlapping symptoms of myocardial ischemia. Takotsubo syndrome (TTS), characterized by stress-induced cardiomyopathy, may share pathophysiological mechanisms with Kounis syndrome and potentially coexist in the same patient.

Case Presentation

We present a case of a 63-year-old patient who developed an allergic reaction to contrast medium administration, leading to dyspnea and chest pain. Electrocardiography revealed a new-onset left bundle-branch block, and echocardiography indicated wall motion abnormalities with apical ballooning, suggestive of TTS. Coronary angiography displayed a chronic total occlusion of the right coronary artery. Laboratory tests revealed elevated inflammatory markers, supporting the diagnosis of Kounis syndrome and TTS.

Conclusion

This case highlights the challenges of diagnosing and managing type II Kounis syndrome associated with concurrent TTS. This underscores the need for tailored therapeutic interventions and comprehensive guidelines to address these complex conditions effectively.
Distribution and developmental timing of zebrafish liver innervation
Authors: Miller Bess M. , Goessling Wolfram
Published: August 2024

Hepatic innervation regulates multiple aspects of liver function, repair and regeneration, and liver denervation is associated with higher rates of metabolic disorders in humans. However, the mechanisms regulating the development of the hepatic nervous system, as well as the role of the hepatic nervous system in liver development and maturation, are still largely unknown. Zebrafish are a widely used model of liver development and regeneration, but hepatic innervation in zebrafish has not yet been described in detail. Here, we examine the extent and developmental timing of hepatic innervation in zebrafish. We demonstrate that innervation is restricted to large bile ducts and blood vessels in both juvenile and adult zebrafish livers, as we find no evidence for direct innervation of hepatocytes. Innervation contacting the periphery of the liver is visible as early as 72 h post-fertilization, while intrahepatic innervation is not established until 21 days post-fertilization. Therefore, zebrafish hepatic innervation resembles that of previously examined fish species, making them an excellent model to investigate both the role of the hepatic nervous system during liver maturation and the mechanisms governing the elaboration of the intrahepatic nerve network between fish and mammals.
Albert Alan Townsend. 22 January 1917—31 August 2010
Authors: Savill A. Mark , Marusic FRS Ivan
Published: August 2024

Alan Townsend is renowned for his significant contributions to understanding turbulence. He began his research career studying nuclear physics but this was disrupted by the Second World War, after which his focus shifted to the study of turbulent fluid flow. Collaborating with George Batchelor (FRS 1957), Townsend conducted pioneering experiments that uncovered the spatially intermittent nature of small-scale turbulence, profoundly shaping subsequent theoretical advances. He further shaped the field by pioneering an approach highlighting the importance of eddies, localized regions of coherent or well-ordered motion within turbulent flows. His work distinguished the eddies underlying different classes of flow, particularly turbulence in open flows, free from solid boundaries, such as jets and wakes, and flows near such boundaries, such as flow over an aeroplane or ship or within a pipe or channel. A significant seminal contribution was his attached eddy hypothesis, which provides the basis of a model for how eddies in surface-bounded flows exert control over the transport of momentum, energy and other properties within the flow. The enduring relevance of this work resonates through contemporary research, challenging established paradigms and guiding ongoing research endeavours across the globe.
A feather star is born: embryonic development and nervous system organization in the crinoid
Antedon mediterranea
Authors: Mercurio Silvia , Gattoni Giacomo , Scarì Giorgio , Ascagni Miriam , Barzaghi Benedetta , Elphick Maurice R. , Croce Jenifer C. , Schubert Michael , Benito-Gutiérrez Elia , Pennati Roberta
Published: August 2024

Crinoids belong to the Echinodermata, marine invertebrates with a highly derived adult pentaradial body plan. As the sister group to all other extant echinoderms, crinoids occupy a key phylogenetic position to explore the evolutionary history of the whole phylum. However, their development remains understudied compared with that of other echinoderms. Therefore, the aim here was to establish the Mediterranean feather star (
Antedon mediterranea
) as an experimental system for developmental biology. We first set up a method for culturing embryos
in vitro
and defined a standardized staging system for this species. We then optimized protocols to characterize the morphological and molecular development of the main structures of the feather star body plan. Focusing on the nervous system, we showed that the larval apical organ includes serotonergic, GABAergic and glutamatergic neurons, which develop within a conserved anterior molecular signature. We described the composition of the early post-metamorphic nervous system and revealed that it has an anterior signature. These results further our knowledge on crinoid development and provide new techniques to investigate feather star embryogenesis. This will pave the way for the inclusion of crinoids in comparative studies addressing the origin of the echinoderm body plan and the evolutionary diversification of deuterostomes.
Proterozoic microfossils continue to provide new insights into the rise of complex eukaryotic life
Authors: Anderson Ross P. , Mughal Sanaa , Wedlake George O.
Published: August 2024

Eukaryotes have evolved to dominate the biosphere today, accounting for most documented living species and the vast majority of the Earth’s biomass. Consequently, understanding how these biologically complex organisms initially diversified in the Proterozoic Eon over 539 million years ago is a foundational question in evolutionary biology. Over the last 70 years, palaeontologists have sought to document the rise of eukaryotes with fossil evidence. However, the delicate and microscopic nature of their sub-cellular features affords early eukaryotes diminished preservation potential. Chemical biomarker signatures of eukaryotes and the genetics of living eukaryotes have emerged as complementary tools for reconstructing eukaryote ancestry. In this review, we argue that exceptionally preserved Proterozoic microfossils are critical to interpreting these complementary tools, providing crucial calibrations to molecular clocks and testing hypotheses of palaeoecology. We highlight recent research on their preservation and biomolecular composition that offers new ways to enhance their utility.
Sensory feedback and central neuronal interactions in mouse locomotion
Authors: Molkov Yaroslav I. , Yu Guoning , Ausborn Jessica , Bouvier Julien , Danner Simon M. , Rybak Ilya A.
Published: August 2024

Locomotion is a complex process involving specific interactions between the central neural controller and the mechanical components of the system. The basic rhythmic activity generated by locomotor circuits in the spinal cord defines rhythmic limb movements and their central coordination. The operation of these circuits is modulated by sensory feedback from the limbs providing information about the state of the limbs and the body. However, the specific role and contribution of central interactions and sensory feedback in the control of locomotor gait and posture remain poorly understood. We use biomechanical data on quadrupedal locomotion in mice and recent findings on the organization of neural interactions within the spinal locomotor circuitry to create and analyse a tractable mathematical model of mouse locomotion. The model includes a simplified mechanical model of the mouse body with four limbs and a central controller composed of four rhythm generators, each operating as a state machine controlling the state of one limb. Feedback signals characterize the load and extension of each limb as well as postural stability (balance). We systematically investigate and compare several model versions and compare their behaviour to existing experimental data on mouse locomotion. Our results highlight the specific roles of sensory feedback and some central propriospinal interactions between circuits controlling fore and hind limbs for speed-dependent gait expression. Our models suggest that postural imbalance feedback may be critically involved in the control of swing-to-stance transitions in each limb and the stabilization of walking direction.
An extensive re-evaluation of evidence and analyses of the Randomised Badger Culling Trial II: In neighbouring areas
Authors: Mills Cathal L. , Woodroffe Rosie , Donnelly Christl A.
Published: August 2024

In the second investigation in a pair of analyses which re-evaluates the Randomised Badger Culling Trial (RBCT), we estimate the effects of proactive badger culling on the incidence of tuberculosis (TB) in cattle populations in unculled neighbouring areas. Throughout peer-reviewed analyses of the RBCT, proactive culling was estimated to have detrimental effects on the incidence of herd breakdowns (i.e. TB incidents) in neighbouring areas. Using previously published, publicly available data, we appraise a variety of frequentist and Bayesian models as we estimate the effects of proactive culling on confirmed herd breakdowns in unculled neighbouring areas. For the during trial period from the initial culls until 4 September 2005, we estimate consistently high probabilities that proactive culling had adverse effects on confirmed herd breakdowns in unculled neighbouring areas, thus supporting the theory of heightened risk of TB for the neighbouring cattle populations. Negligible culling effects are estimated in the post-trial period across the statistical approaches and imply unsustained long-term effects for unculled neighbouring areas. Therefore, when considered alongside estimated beneficial effects within proactive culling areas, these conflicting adverse side effects render proactive culling complex, and thus, decision making regarding potential culling strategies should include (i) ecological, geographical and scientific considerations and (ii) cost–benefit analyses.
Structured methods for parameter inference and uncertainty quantification for mechanistic models in the life sciences
Authors: Plank Michael J. , Simpson Matthew J.
Published: August 2024

Parameter inference and uncertainty quantification are important steps when relating mathematical models to real-world observations and when estimating uncertainty in model predictions. However, methods for doing this can be computationally expensive, particularly when the number of unknown model parameters is large. The aim of this study is to develop and test an efficient profile likelihood-based method, which takes advantage of the structure of the mathematical model being used. We do this by identifying specific parameters that affect model output in a known way, such as a linear scaling. We illustrate the method by applying it to three toy models from different areas of the life sciences: (i) a predator–prey model from ecology; (ii) a compartment-based epidemic model from health sciences; and (iii) an advection–diffusion reaction model describing the transport of dissolved solutes from environmental science. We show that the new method produces results of comparable accuracy to existing profile likelihood methods but with substantially fewer evaluations of the forward model. We conclude that our method could provide a much more efficient approach to parameter inference for models where a structured approach is feasible. Computer code to apply the new method to user-supplied models and data is provided via a publicly accessible repository.
Rational curvature invariants for 2-complexes
Authors: Wilton Henry
Published: August 2024

New invariants for two-dimensional cell complexes are defined, which can be interpreted as curvature bounds. These invariants are proved to be rational and computable in a companion article. This document is a survey that collects theorems about these invariants, computes examples and lays out a programme of conjectures.
Widespread cultural change in declining populations of Amazon parrots
Authors: Dahlin Christine R. , Smith-Vidaurre Grace , Genes Molly K. , Wright Timothy F.
Published: August 2024

Species worldwide are experiencing anthropogenic environmental change, and the long-term impacts on animal cultural traditions such as vocal dialects are often unknown. Our prior studies of the yellow-naped amazon (
Amazona auropalliata
) revealed stable vocal dialects over an 11-year period (1994–2005), with modest shifts in geographic boundaries and acoustic structure of contact calls. Here, we examined whether yellow-naped amazons maintained stable dialects over the subsequent 11-year time span from 2005 to 2016, culminating in 22 years of study. Over this same period, this species suffered a dramatic decrease in population size that prompted two successive uplists in IUCN status, from vulnerable to critically endangered. In this most recent 11-year time span, we found evidence of geographic shifts in call types, manifesting in more bilingual sites and introgression across the formerly distinct North–South acoustic boundary. We also found greater evidence of acoustic drift, in the form of new emerging call types and greater acoustic variation overall. These results suggest cultural traditions such as dialects may change in response to demographic and environmental conditions, with broad implications for threatened species.
Widespread convergence towards functional optimization in the lower jaws of crocodile-line archosaurs
Authors: Rawson James R. G. , Deakin William J. , Stubbs Thomas L. , Smith Thomas J. , Rayfield Emily J. , Donoghue Phillip C. J.
Published: August 2024

Extant crocodilian jaws are subject to functional demands induced by feeding and hydrodynamics. However, the morphological and ecological diversity of extinct crocodile-line archosaurs is far greater than that of living crocodilians, featuring repeated convergence towards disparate ecologies including armoured herbivores, terrestrial macropredators and fully marine forms. Crocodile-line archosaurs, therefore, present a fascinating case study for morphological and functional divergence and convergence within a clade across a wide range of ecological scenarios. Here, we build performance landscapes of two-dimensional theoretical jaw shapes to investigate the influence of strength, speed and hydrodynamics in the morphological evolution of crocodile-line archosaur jaws, and test whether ecologically convergent lineages evolved similarly optimal jaw function. Most of the 243 sampled jaw morphologies occupy optimized regions of theoretical morphospace for either rotational efficiency, resistance to Von Mises stress, hydrodynamic efficiency or a trade-off between multiple functions, though some seemingly viable shapes remain unrealized. Jaw speed is optimized only in a narrow region of morphospace whereas many shapes possess optimal jaw strength, which may act as a minimum boundary rather than a strong driver for most taxa. This study highlights the usefulness of theoretical morphology in assessing functional optimality, and for investigating form–function relationships in diverse clades.
Heat tolerance, oxidative stress response tuning and robust gene activation in early-stage
Drosophila melanogaster
embryos
Authors: Mikucki Emily E. , O’Leary Thomas S. , Lockwood Brent L.
Published: August 2024

In organisms with complex life cycles, life stages that are most susceptible to environmental stress may determine species persistence in the face of climate change. Early embryos of
Drosophila melanogaster
are particularly sensitive to acute heat stress, yet tropical embryos have higher heat tolerance than temperate embryos, suggesting adaptive variation in embryonic heat tolerance. We compared transcriptomic responses to heat stress among tropical and temperate embryos to elucidate the gene regulatory basis of divergence in embryonic heat tolerance. The transcriptomes of tropical and temperate embryos differed in both constitutive and heat-stress-induced responses of the expression of relatively few genes, including genes involved in oxidative stress. Most of the transcriptomic response to heat stress was shared among all embryos. Embryos shifted the expression of thousands of genes, including increases in the expression of heat shock genes, suggesting robust zygotic gene activation and demonstrating that, contrary to previous reports, early embryos are not transcriptionally silent. The involvement of oxidative stress genes corroborates recent reports on the critical role of redox homeostasis in coordinating developmental transitions. By characterizing adaptive variation in the transcriptomic basis of embryonic heat tolerance, this study is a novel contribution to the literature on developmental physiology and developmental genetics.
Direct assessment of tropical tuna abundance from their associative behaviour around floating objects
Authors: Baidai Yannick , Dupaix Amaël , Dagorn Laurent , Gaertner Daniel , Deneubourg Jean-Louis , Duparc Antoine , Capello Manuela
Published: August 2024

Managing populations of wild harvested species requires the ability to regularly provide accurate abundance assessments. For most marine species, changes in abundance can only be monitored indirectly, using methods reliant on harvest-based indices, with significant inherent limitations surrounding the estimation and standardization of harvest effort. Tropical tunas are some of the most exploited marine species in the world and are among several species in critical need of alternative methods for estimating abundance. Addressing this concern, we developed the Associative Behaviour-Based abundance Index (ABBI), designed to provide direct abundance estimates for animals, which exhibit an associative behaviour with aggregation sites. Its implementation in the western Indian Ocean on skipjack tuna (
Katsuwonus pelamis
), yellowfin tuna (
Thunnus albacares
) and bigeye tuna (
Thunnus obesus
), revealed similar trajectories in their relative abundance. The ABBI stands as a potentially promising alternative to enhance traditional tropical tuna stock assessments methods, as well as a new opportunity to assess the abundance of other wild species that display an associative behaviour with physical structures found in their natural environment.
Food chain without giants: modelling the trophic impact of bowhead whaling on little auk populations in the Atlantic Arctic
Authors: Thepault Amaury , Rodrigues Ana S. L. , Drago Laetitia , Grémillet David
Published: August 2024

In the Atlantic Arctic, bowhead whales (
Balaena mysticetus
) were nearly exterminated by European whalers between the seventeenth and nineteenth centuries. The collapse of the East Greenland–Svalbard–Barents Sea population, from an estimated 50 000 to a few hundred individuals, drastically reduced predation on mesozooplankton. Here, we tested the hypothesis that this event strongly favoured the demography of the little auk (
Alle alle
), a zooplanktivorous feeder competitor of bowhead whales and the most abundant seabird in the Arctic. To estimate the effect of bowhead whaling on little auk abundance, we modelled the trophic niche overlap between the two species using deterministic simulations of mesozooplankton spatial distribution. We estimated that bowhead whaling could have led to a 70% increase in northeast Atlantic Arctic little auk populations, from 2.8 to 4.8 million breeding pairs. While corresponding to a major population increase, this is far less than predicted by previous studies. Our study illustrates how a trophic shift can result from the near extirpation of a marine megafauna species, and the methodological framework we developed opens up new opportunities for marine trophic modelling.