Subcritical Research Articles

A re-assessment of Dr Robert Knox and his contribution to early evolution science.

Dr Robert Knox was publicly scorned and disgraced for his unwitting involvement in the Burke and Hare serial murders in 1828. Far less appreciated is his brilliance as an anatomist and he espoused the European movement in Transcendental Anatomy, which aimed to uncover the laws governing what we now know as evolution and the origin of species. Knox fully embraced Transcendental Anatomy during a sojourn in Paris and taught it on his return to Edinburgh, where there was a critical mass of like-minded Transcendental Anatomists. Charles Darwin spent 1825-1827 as a medical student in Edinburgh when Transcendental Anatomy was at its peak amongst the city's anatomists, and evolution - then known as transmutation - was a source of great interest and controversy. Knox intended to research Transcendental Anatomy, but this was thwarted by conflicting demands on his time in the second half of the 1820s decade and the Burke and Hare tragedy. He did, however, go on to champion Transcendental Anatomy and write extensively on it.

Participation of Female Workforce in the Construction Sector in Sri Lanka: Challenges and Policy Implications

It is widely accepted that women do not have equal rights and status, particularly in developing nations. The various theoretical and empirical studies show gender inequalities in salaries, earnings, income and pay scales, and the construction sector is no exception. This study highlighted potential areas for women in the construction sector labour market by analyzing market and employment related trends and requirements on the demand and supply sides. Further, the study identified the challenges and necessary policy implications for enhancing female labour force participation in the construction sector in Sri Lanka. Many female workforces believe that developing a critical mass of women in different occupations in the construction sector would encourage more women to enter the business. Many studies have shown that since women have poor levels of skills and are either not given or unaware of skill upgrading opportunities, they are unable to enter or flourish in construction-related industries. In addition, interruptions in careers, limitations on flexible working hours, engaging in precarious work due to household responsibilities, and the gender pay gap are some other important factors that limit labour market activities by women, thus lowering social protection coverage for females. Besides socio-cultural and religious barriers, the data also revealed that women face sexual harassment, which discourages them from continuing their jobs in the construction sector for a long time.

Reexamination of Multi-level Representation and Critical Mass: The Roles of Black Leadership and Its Relationship With Street-Level Officers in Police Killings

The study’s goal is to examine the multi-level representation in the context of cooperation and support between black police chiefs and street-level officers. Another goal here is to re-examine and propose different critical mass models in policing. The study uses police killing data from 2014 to 2017 in the United States. Using multi-level modeling techniques, the existing critical mass model, which assumes a single threshold, is not supported. Instead, the study finds that the mutual support model is supported, showing that street-level black officers need support from the black chief, while the black chief also needs further support from street-level officers. Simultaneously, it finds that the presence of a black chief shifts the threshold of street-level representation to a lower level, showing a close relationship between mutual support and critical mass due to a similar mechanism. The findings suggest the importance of police leadership.

A network perspective on tourism waste management: An evolutionary game analysis of stakeholders' participation in the Third Pole region

There is a striking absence of complex network models and extensive analysis of behavioral factors in the field of waste management research. Moreover, research on effective collaboration among different stakeholders in tourism waste management in the Third Pole region is currently lacking, despite the increasing involvement of various groups. Therefore, this paper aims to explore the cooperative relationship between multiple stakeholders in tourism waste management using the Lulang Scenic Area as a case study. A field investigation and complex network evolutionary game simulation were used to identify the cooperation dynamics between multiple stakeholders. The results indicate the following. (1) The stakeholder network characterized by small-world dynamics has efficient information diffusion and cooperation. (2) A threshold value for positive externalities and returns on investment exists, beyond which stakeholders are more inclined to participate in sustainable waste management. (3) Incentives below the threshold attract direct stakeholders in waste generation and management, whereas incentives above it draws in a broader range of stakeholders, primarily indirect stakeholders. (4) A critical mass of cooperative stakeholders tends to create a demonstration effect that encourages additional participation, supporting the growth of cooperative networks in tourism waste management. This paper innovatively shows the potential of a cooperation strategy between multiple stakeholders strengthened by appropriate incentives.

Do ‘Lehman Sisters’ work in China? Women on boards and bank risk

We investigate how women on boards impact bank risk in China. Using a merged dataset containing 83 Chinese banks for the period of 2006–2019, we find that more women on boards could reduce bank risk in China. We further provide the evidence that risk-averse nature of women directors motivates them to organize more board meetings in order to lower bank risk. Additionally, women executive directors play the main role in reducing bank risk and a critical mass (three or more) of women directors intensifies the negative impact on bank risk. Our results still hold when we use lagged variables, GMM regression technique, instrumental variable and DID estimation. Our study could provide valuable empirical advice for the policy makers in both China and other developing countries.

Does the strength of women in the upper echelon influence earnings quality? The application of critical mass theory

Globally, several financial scandals were witnessed within the first decade of the 21st century that necessitated a robust corporate governance mechanism to improve financial reporting quality. Empirical evidence shows that men dominate the boards involved in these scandals. In an attempt to restore the confidence of stakeholders in the financial report, financial regulatory authorities in European Union economies recommend a well-constituted gender-diverse board where the marginalised gender is at least 40 percent of the board. However, in Nigeria, there is little research on women's participation in corporate board decisions taken into cognizance of critical mass theory. Thus, the study investigates how the critical mass of female representation on the corporate board and audit committee affects earnings quality. The study employs a longitudinal design by collecting secondary data on eleven deposit money banks from 2011-2022. The study uses data collected after testing endogeneity problems using Hausman's test. The results show that females on the board and audit committee significantly affect the quality of earnings when reaching the critical mass threshold. The study provides policy implications for supporting more significant involvement of women in board and audit committees based on business cases rather than social justice. Hence, this study proposes a mandatory thirty percent threshold compliance for board gender diversity, which the Central Bank of Nigeria voluntarily recommended.

Unpacking women’s power on corporate boards: gender reward in board composition

AbstractParticipation of women on corporate boards has long been a topic of debate in academia and practice. Yet, the threshold of women's participation in a corporate board to obtain a synergetic impact on corporate sustainability performance remains to be examined. Data from 19 European countries, having 2640 firm-year of observation, this study revealed that women on boards positively affect corporate sustainability performance in the European context, with an approximately 30% participation of women on boards (WoB) ensuring synergetic impact. This study further revealed that after the threshold of WoB participation, the market value of companies tends to be negative in the European setting. An indication of investors' reactions. The issue was first examined through the lens of the resource-based view, social role, agency and critical mass theories and then empirically tested. To reach a conclusion, this study employs both static and dynamic econometric models; thus, the finding is consistent and empirically robust. The research findings contribute to the current discussion on corporate governance and corporate sustainability performances issues, especially in the European context, and have implications for researchers, business practitioners, and policymakers.

Axion star explosions: A new source for axion indirect detection

If dark matter is composed of axions, then axion stars form in the cores of dark matter halos. These stars are unstable above a critical mass, decaying to radio photons that heat the intergalactic medium, offering a new channel for axion indirect detection. We recently provided the first accurate calculation of the axion decay rate due to axion star mergers. In this work we show how existing data concerning the CMB optical depth leads to strong constraints on the axion photon coupling in the mass range 10−14 eV≲ma≲10−8 eV. Axion star decays lead to efficient reionization of the intergalactic medium during the dark ages. By comparing this nonstandard reionization with Planck legacy measurements of the Thomson optical width, we show that couplings in the range 10−14 GeV−1≲gaγγ≲10−10 GeV−1 are excluded for our benchmark model of axion star abundance. Future measurements of the 21 cm emission of neutral hydrogen at high redshift could improve this limit by an order of magnitude or more, providing complementary indirect constraints on axion dark matter in parameter space also targeted by direct detection haloscopes. Published by the American Physical Society 2024

Condition Monitoring of Wind Turbine Drivetrain Bearings

Abstract As an extremely valuable and reliable energy source, the renewable energy is developing around the world at an unprecedented pace. By the end of 2022, the global installed capacity of offshore wind turbines is expected to reach 46.4 GW, among which 33.9 GW in Europe. Efficiencies in Operations and Maintenance (O&M) offer potential to achieve significant cost savings as it accounts for around 20%–30% of overall offshore wind farm costs. A recent study of approximately 350 offshore wind turbines indicates that gearboxes might have to be replaced as early as 6.5 years. Therefore sensing and condition monitoring (CM) systems are needed in order to obtain reliable information on the state and condition of different critical parts. The development and use of such technologies will allow companies to schedule actions at the right time. The reduced costs of O&M enable the wind energy at a competitive price thus strengthening productivity of the wind energy sector. At the academic level, a plethora of methodologies have been proposed during the last decades focusing toward early and accurate fault detection. Among others, Envelope Analysis is one of the most important methodologies, where the envelope of the vibration signal is estimated, usually after filtering around a selected frequency band excited by impacts due to the faults. Different tools, such as Kurtogram, have been proposed in order to accurately select the optimum filter parameters (center frequency and bandwidth). Cyclostationary analysis and corresponding methodologies, i.e., the cyclic spectral correlation and the cyclic spectral coherence, have been proved as powerful tools for CM. On the other hand the application, test, and evaluation of such tools in general industrial cases is still rather limited. Therefore the main aim of this paper is the application and evaluation of advanced diagnostic techniques and diagnostic indicators, including the Enhanced Envelope Spectrum and the Spectral Flatness on real-world vibration data collected from vibration sensors on gearboxes in multiple wind turbines over an extended period of time of nearly four years. The diagnostic indicators are compared with classical statistic time and frequency indicators, i.e., Kurtosis, Crest Factor, etc. and their effectiveness is evaluated based on the successful detection of two failure events.

The critical mass curve and chemotactic collapse of a two-species chemotaxis system with two chemicals

This paper considers the following two-species chemotaxis system with two chemicals ut=Δu−∇⋅(u∇v),x∈Ω,t>0,0=Δv−αv+w,x∈Ω,t>0,wt=Δw−∇⋅(w∇z),x∈Ω,t>0,0=Δz−γz+u,x∈Ω,t>0subject to the homogeneous Neumann boundary condition with α,γ>0, where Ω⊂R2 is a smooth bounded domain. In the previous paper [Yu et al, Criteria on global boundedness versus finite time blow-up to a two-species chemotaxis system with two chemicals, Nonlinearity 31 (2018) 502–514], we proved that the system possesses finite-time blow-up solutions provided (0.1)mumw−2π(mu+mw)>0,where mu and mw denote the initial masses of u and w respectively. In this paper, we first establish the critical mass curve mumw−2π(mu+mw)=0 by proving that solutions are globally bounded whenever (0.2)mumw−2π(mu+mw)<0,which means the blow-up condition (0.1) is optimal. Based on this, we further show for the blow-up region (0.1) that (u(x,t)dx,w(x,t)dx) forms a delta function singularity at the blow-up point x0 as t→Tmax with the collapse mass (Mx0u,Mx0w) satisfying Mx0uMx0w−M∗(Mx0u+Mx0w)≥0,where M∗=4π for x0∈Ω and M∗=2π for x0∈∂Ω.

Open innovation in a smart city context: the case of Sejong smart city initiative

Open innovation in a smart city context: the case of Sejong smart city initiative

How sustainable is OpenStreetMap? Tracking individual trajectories of editing behavior

ABSTRACT OpenStreetMap (OSM) has been playing increasingly important roles in location-based services, urban planning, tourism, and disaster management. In this paper, we examine a fundamental issue: can OSM reliably provide its services in the long run? To address this sustainable issue, we propose (1) inner cycle of career stages (i.e. activity levels) for monitoring the sustainable status of OSM and (2) critical mass theory for identifying driving factors that make OSM sustain. These new tools are used to track individual trajectories of editing behavior in 2005–2021. Our results suggest that OSM has been self-sustaining up to now and does not show a sign of decline yet. This is supported by the ever-decreasing turnover time and stabilized turnover rate. Together with the finding that most contributors transitioned to a higher career stage within a month, we identify an accelerated socialization process within OSM. We find further that it is the critical mass of people rather than content that makes OSM sustain. This contrasts with the common wisdom: recruiting more people with small contributions is far more important to the long-term growth of OSM than relying on a group of core members with large contributions. Implications and recommendations are critically discussed.

Beyond dominance and Nash: Ranking equilibria by critical mass

Strategic interactions pose central issues that are not adequately explained by the traditional concepts of dominant strategy equilibrium (DSE), Nash equilibrium (NE), and their refinements. A comprehensive analysis of equilibrium concepts within the von Neumann-Nash framework of n-person optimization reveals a decreasing hierarchy of n nested concepts ranging from DSE to NE. These concepts are defined by the “critical mass,” the number of players needed to adopt and sustain the play of a strategy profile as an equilibrium. In games with n>2 players, the n−2 intermediate concepts explain strategic issues in large social systems, implementation, decentralization, as well as replication studied in economics, operations management, and political games.

A Global Semianalytic Model of the First Stars and Galaxies Including Dark Matter Halo Merger Histories

We present a new self-consistent semianalytic model of the first stars and galaxies to explore the high-redshift (z ≥ 15) Population III (PopIII) and metal-enriched star formation histories. Our model includes the detailed merger history of dark matter halos generated with Monte Carlo merger trees. We calibrate the minimum halo mass for PopIII star formation from recent hydrodynamical cosmological simulations that simultaneously include the baryon–dark matter streaming velocity, Lyman–Werner (LW) feedback, and molecular hydrogen self-shielding. We find an overall increase in the resulting star formation rate density (SFRD) compared to calibrations based on previous simulations (e.g., the PopIII SFRD is over an order of magnitude higher at z = 35−15). We evaluate the effect of the halo-to-halo scatter in this critical mass and find that it increases the PopIII stellar mass density by a factor ∼1.5 at z ≥ 15. Additionally, we assess the impact of various semianalytic/analytic prescriptions for halo assembly and star formation previously adopted in the literature. For example, we find that models assuming smooth halo growth computed via abundance matching predict SFRDs similar to the merger tree model for our fiducial model parameters, but that they may underestimate the PopIII SFRD in cases of strong LW feedback. Finally, we simulate subvolumes of the Universe with our model both to quantify the reduction in total star formation in numerical simulations due to a lack of density fluctuations on spatial scales larger than the simulation box, and to determine spatial fluctuations in SFRD due to the diversity in halo abundances and merger histories.

Comments on the Frisch-Peierls Estimate of the Critical Mass of a Uranium Fission Bomb

The Frisch-Peierls memorandum of March 1940 opened the way to nuclear weapons through its conclusion that the critical mass for an explosive chain reaction in 235U could be as small as 0.6 kg. This gross underestimate was based on the conjecture that the cross section for the fission of 235U with fast neutrons was 10 barns. Though this value turned out to be far too high, it is argued here that the choice made was not unreasonable at the time.

An empirical analysis of SDG disclosure (SDGD) and board gender diversity: insights from the banking sector in an emerging economy

AbstractThere has been a recent surge in interest in academic research and public discourse surrounding the Sustainable Development Goals (SDGs). This study examines the level of SDG disclosure (SDGD) in Bangladeshi banking companies and explores its relationship with board gender diversity. An automated keyword search is applied to measure SDGD in the annual reports of publicly traded commercial banks. Based on agency, resource dependence, and stakeholder theories, this study hypothesises that a higher presence of female directors on the board is associated with greater commitment and contribution to SDGs, as evident in SDGD. The findings reveal a consistent increase in SDGD from 2015 to 2020 and confirm a significant positive relationship between board gender diversity and SDGD. The results remain consistent following robustness tests, including one-step and two-step system (dynamic) GMM estimations. Also, the study provides evidence that a critical mass of at least three female directors is necessary to establish a significant positive relationship between board gender diversity and SDGD. The implications of this study are twofold: firstly, it provides preliminary insights into the state of SDGD in the banking industry, which can inform regulators in assessing corporate engagement to SDGs and issuing disclosure guidance for the interest of the stakeholders. Secondly, the study highlights the importance of gender diversity on boards, as more female representation is associated with increasing SDGD. Such empirical findings imply that banking companies should consider appointing more female directors to their boards to advance SDG initiatives. Policymakers can utilise these findings to formulate regulations, particularly regarding the minimum number of female directors on corporate boards. This research contributes to the limited SDGD literature in the emerging economy context, offering insights into how board gender diversity is associated with SDGD.

Telemedicine in Service of Family Doctors in North Macedonia: Search for the New Frontier for Medical Professionals.

Introduction: Innovative medical technologies such as telemedicine, telehealth, and artificial intelligence have great potential in North Macedonia. Our nation was a leader in the region in advancing internet connections. A key barrier to wider adoption has been human resources. Material and Methods: Family doctors are skilled and trained enough to accept and use these technologies in everyday work. In our School of Family Medicine, we thought that additional training was necessary. This was the key objective of our task-if telemedicine and telehealth are presented to a critical mass of doctors as yet another tool that will make their day-to-day work easier, the "chain reaction" of adopting and applying telemedicine and telehealth would not be stopped. Discussion: To further study this objective, we started with a pilot project with a course in telemedicine and telehealth for future family medicine specialists. Telepsychiatry and teledermatology were the first modules to be taught. In addition, telehealth care equipment was also presented to participants. Conclusion: Participants' reactions were very positive.

Effect of female representation in audit committees on non-audit fees: evidence from China

PurposeThis study aims to investigate whether gender diversity in audit committees affects the purchase of nonaudit services in China. Results from family and nonfamily firms are compared and the critical mass participation of females are further examined.Design/methodology/approachThe sample comprises 1,834 Chinese listed companies from 2012 to 2021, among which 910 are family firms. The Heckman (1979) two-stage model is used to mitigate the potential endogeneity issue in the selection of gender diversity. Propensity score matching is also used to further alleviate the endogeneity problem in relation to family firms.FindingsResults show a significant and negative correlation between the gender diversity in audit committees and nonaudit service fees. This association is more apparent in nonfamily than in family firms. Findings are consistent and robust to endogeneity tests and sensitivity analyses. The analysis of critical mass and symbolic participation shows that three female directors can more significantly restrain nonaudit fees than one to two females on the board.Practical implicationsThis study contributes to literature on resource dependence theory, which posits that audit committees help enterprises establish contact with auditors, improve the company legitimacy, assist in communication and provide relevant expertise. This study also relates to agency theory, which holds that differences in the severity of types I and II agency problems between family and nonfamily firms lead to differences in auditor selection and related costs.Originality/valueExtending from previous research on the relation between the gender diversity in audit committees and nonaudit fees, the present study delves into this connection within the context of China, an emerging economy. As a result, this investigation offers novel insights and expands upon current knowledge. In addition, the correlation between the gender diversity of audit committees and nonaudit fees is explored for family and nonfamily firms.

Critical mass condition of majority bureaucratic behavioral change in representative bureaucracy: a theoretical clarification and a nonparametric exploration

Abstract Representative bureaucracy theory examines how bureaucrats’ demographics impact outcomes for clients with shared identities, with “critical mass” posited as an enabling condition. Yet empirical evidence is mixed regarding where this threshold stands. To reconcile these inconsistencies, this study emphasizes the need to first clarify the mechanisms that underpin critical mass requirements. Specifically, I attend to how majority behavior changes due to enhanced representation and evaluate corresponding critical mass condition. Nonparametric analyses of traffic stop data in two states find that, in Washington, the critical mass where White officers show reduced bias towards Black drivers occurs when Black officers constitute 6–9 percent of the force. In South Carolina, similar shifts occur at 9–11 and 19–23 percent Black representation. While findings indicate improved policing towards Black drivers, increased representation still falls short of achieving full parity between Black and White drivers. No significant critical mass is observed for Hispanic representation in either state.

Strategies to decrease inequalities in cancer therapeutics, care and prevention: Proceedings on a conference organized by the Pontifical Academy of Sciences and the European Academy of Cancer Sciences, Vatican City, February 23-24, 2023.

Analyses of inequalities related to prevention and cancer therapeutics/care show disparities between countries with different economic standing, and within countries with high Gross Domestic Product. The development of basic technological and biological research provides clinical and prevention opportunities that make their implementation into healthcare systems more complex, mainly due to the growth of Personalized/Precision Cancer Medicine (PCM). Initiatives like the USA-Cancer Moonshot and the EU-Mission on Cancer and Europe's Beating Cancer Plan are initiated to boost cancer prevention and therapeutics/care innovation and to mitigate present inequalities. The conference organized by the Pontifical Academy of Sciences in collaboration with the European Academy of Cancer Sciences discussed the inequality problem, dependent on the economic status of a country, the increasing demands for infrastructure supportive of innovative research and its implementation in healthcare and prevention programs. Establishing translational research defined as a coherent cancer research continuum is still a challenge. Research has to cover the entire continuum from basic to outcomes research for clinical and prevention modalities. Comprehensive Cancer Centres (CCCs) are of critical importance for integrating research innovations to preclinical and clinical research, as for ensuring state-of-the-art patient care within healthcare systems. International collaborative networks between CCCs are necessary to reach the critical mass of infrastructures and patients for PCM research, and for introducing prevention modalities and new treatments effectively. Outcomes and health economics research are required to assess the cost-effectiveness of new interventions, currently a missing element in the research portfolio. Data sharing and critical mass are essential for innovative research to develop PCM. Despite advances in cancer research, cancer incidence and prevalence is growing. Making cancer research infrastructures accessible for all patients, considering the increasing inequalities, requires science policy actions incentivizing research aimed at prevention and cancer therapeutics/care with an increased focus on patients' needs and cost-effective healthcare.