Jetting bubbles observed by x-ray holography at a free-electron laser: internal structure and the effect of non-axisymmetric boundary conditions

Abstract

In this work, we study the jetting dynamics of individual cavitation bubbles using x-ray holographic imaging and high-speed optical shadowgraphy. The bubbles are induced by a focused infrared laser pulse in water near the surface of a flat, circular glass plate, and later probed with ultrashort x-ray pulses produced by an x-ray free-electron laser (XFEL). The holographic imaging can reveal essential information of the bubble interior that would otherwise not be accessible in the optical regime due to obscuration or diffraction. The influence of asymmetric boundary conditions on the jet’s characteristics is analysed for cases where the axial symmetry is perturbed and curved liquid filaments can form inside the cavity. The x-ray images demonstrate that when oblique jets impact the rigid boundary, they produce a non-axisymmetric splash which grows from a moving stagnation point. Additionally, the images reveal the formation of complex gas/liquid structures inside the jetting bubbles that are invisible to standard optical microscopy. The experimental results are analysed with the assistance of full three-dimensional numerical simulations of the Navier–Stokes equations in their compressible formulation, which allow a deeper understanding of the distinctive features observed in the x-ray holographic images. In particular, the effects of varying the dimensionless stand-off distances measured from the initial bubble location to the surface of the solid plate and also to its nearest edge are addressed using both experiments and simulations. A relation between the jet tilting angle and the dimensionless bubble position asymmetry is derived. The present study provides new insights into bubble jetting and demonstrates the potential of x-ray holography for future investigations in this field.

Navigating the myriad of corporate quality standards: a CSR and stakeholder perspective

Abstract

Quality standards (QS) (e.g., ISO 9001) play an important role in assuring the quality of goods and services for organizational stakeholders on a global scale. Recent work has highlighted the role of QS in communicating corporate social responsibility (CSR) practices to a firm’s stakeholders making both the QS adoption decision and the timing of adoption of immense strategic importance to top managers. However, the types of QS and their intended and unintended beneficiaries vary widely, making it difficult for managers to choose QS that are in accord with their CSR goals. Further, current economic (cost/benefit) and institutionally-based theoretical approaches do not provide managers with adequate guidance in making strategic adoption decisions. Rapid developments in QS practices have also made it difficult for researchers to incorporate them into CSR theory. Drawing upon a literature review of QSs and stakeholder theory, this study presents a QS framework and taxonomy that integrates QS adoption timing and beneficiaries. The framework also presents four configurations of QS adopters and their associated beneficiary stakeholder groups, enabling both researchers and practitioners to more completely understand the complex nature of stakeholder pressures on organizations.

Analysis of brain and blood single-cell transcriptomics in acute and subacute phases after experimental stroke

Abstract

Cerebral ischemia triggers a powerful inflammatory reaction involving peripheral leukocytes and brain resident cells that contribute to both tissue injury and repair. However, their dynamics and diversity remain poorly understood. To address these limitations, we performed a single-cell transcriptomic study of brain and blood cells 2 or 14 days after ischemic stroke in mice. We observed a strong divergence of post-ischemic microglia, monocyte-derived macrophages and neutrophils over time, while endothelial cells and brain-associated macrophages showed altered transcriptomic signatures at 2 days poststroke. Trajectory inference predicted the in situ trans-differentiation of macrophages from blood monocytes into day 2 and day 14 phenotypes, while neutrophils were projected to be continuously de novo recruited from the blood. Brain single-cell transcriptomes from both female and male aged mice were similar to that of young male mice, but aged and young brains differed in their immune cell composition. Although blood leukocyte analysis also revealed altered transcriptomes after stroke, brain-infiltrating leukocytes displayed higher transcriptomic divergence than their circulating counterparts, indicating that phenotypic diversification occurs within the brain in the early and recovery phases of ischemic stroke. A portal (https://anratherlab.shinyapps.io/strokevis/) is provided to allow user-friendly access to our data.

Twitter’s pulse on hydrogen energy in 280 characters: a data perspective

Abstract

Uncovering the public discourse on hydrogen energy is essential for understanding public behaviour and the evolving nature of conversations over time and across different regions. This paper presents a comprehensive analysis of a large multilingual dataset pertaining to hydrogen energy collected from Twitter spanning a decade (2013–2022) using selected keywords. The analysis aims to explore various aspects, including the temporal and spatial dimensions of the discourse, factors influencing Twitter engagement, user engagement patterns, and the interpretation of conversations through hashtags and ngrams. By delving into these aspects, this study offers valuable insights into the dynamics of public discourse surrounding hydrogen energy and the perceptions of social media users.

Twitter’s pulse on hydrogen energy in 280 characters: a data perspective

Abstract

Uncovering the public discourse on hydrogen energy is essential for understanding public behaviour and the evolving nature of conversations over time and across different regions. This paper presents a comprehensive analysis of a large multilingual dataset pertaining to hydrogen energy collected from Twitter spanning a decade (2013–2022) using selected keywords. The analysis aims to explore various aspects, including the temporal and spatial dimensions of the discourse, factors influencing Twitter engagement, user engagement patterns, and the interpretation of conversations through hashtags and ngrams. By delving into these aspects, this study offers valuable insights into the dynamics of public discourse surrounding hydrogen energy and the perceptions of social media users.

Mathematical Model and AI Integration for COVID-19: Improving Forecasting and Policy-Making

Abstract

In this work, a new susceptible–exposed–infectious–recovered (SEIR) compartmental model is proposed which has additional media influence for precise quantization of the coronavirus disease 2019 (COVID-19). In the proposed model, first-order ordinary differential equations (ODEs) are used for the formulation of basic reproduction number, whereas genetic algorithm (GA) is used for its estimation. The inclusion of climatic parameters, governmental impact, and human behavioral response toward the disease provides an upper hand in determining the dynamics of its transmissibility, thereby indicating their significance in precising the outcomes. In addition, the future trends for the new normalized confirmed cases of COVID-19 are predicted using the long short-term memory (LSTM) model which helps in evaluating and modifying the current preventive actions taken to improve the situation. The robustness of the proposed model is measured by five different error functions which are tested in five different countries. According to the experimental results, this is observed that the proposed model has a smaller prediction deviation as well and the proposed scheme outperforms state-of-the-art models of COVID-19.

Mathematical Model and AI Integration for COVID-19: Improving Forecasting and Policy-Making

Abstract

In this work, a new susceptible–exposed–infectious–recovered (SEIR) compartmental model is proposed which has additional media influence for precise quantization of the coronavirus disease 2019 (COVID-19). In the proposed model, first-order ordinary differential equations (ODEs) are used for the formulation of basic reproduction number, whereas genetic algorithm (GA) is used for its estimation. The inclusion of climatic parameters, governmental impact, and human behavioral response toward the disease provides an upper hand in determining the dynamics of its transmissibility, thereby indicating their significance in precising the outcomes. In addition, the future trends for the new normalized confirmed cases of COVID-19 are predicted using the long short-term memory (LSTM) model which helps in evaluating and modifying the current preventive actions taken to improve the situation. The robustness of the proposed model is measured by five different error functions which are tested in five different countries. According to the experimental results, this is observed that the proposed model has a smaller prediction deviation as well and the proposed scheme outperforms state-of-the-art models of COVID-19.

How cultural competence is conceptualised, developed and delivered in pharmacy education: a systematic review

Abstract

Background

It is important to have a pharmacy workforce that is culturally competent to recognise a patient’s health beliefs to improve medication adherence and reduce poor treatment outcomes.

Aim

This systematic review aimed to identify, critically appraise and summarise how cultural competency is conceptualised, developed and embedded in pre-qualification pharmacy education.

Method

Medline, Scopus, PsychInfo, Web of Knowledge, CINAHL, and Embase databases were searched for relevant papers published in English between January 2012 and December 2021, following PRISMA guidelines. Data from included papers were thematically analysed. Educational quality of papers was appraised using the GREET criteria. This systematic review was registered on PROSPERO, CRD42021295875.

Results

The review included 47 papers (46 studies) with 18 papers meeting ≥ 9 points on the GREET criteria thus considered of good educational quality. Forty papers focused on educational interventions implemented to pharmacy students only, the remaining included students from different health disciplines. Half of the educational interventions focused on cultural competence in general. Most educational interventions lasted over a week and 21 were compulsory. Cultural competence conceptualisation varied; a focus on knowledge about different cultures or on culturally competent behaviours or a continuum with knowledge at one end and behaviour at the other.

Conclusion

There is variation in how cultural competence is embedded in pharmacy programmes, which could be a reflection of the differences in how educators conceptualised cultural competence. Further research is needed to develop a unified understanding of the meaning of cultural competence and how it can be embedded in pharmacy education.

Exploring the Impact of Incivility on Psychological Distress: The Unique Lived Experiences of Women Identifying as Indigenous and as part of the LGBTQ + Community

Abstract

Organizations are increasingly facing complex issues related to diversity and inclusion. Although overt forms of discrimination might have declined significantly, researchers are now alarmed in the face of insidious forms of “modern” discrimination that are flying under organizational radars despite policies and laws. While incivility has been broadly conceptualized and examined as “generalized” behaviors in organizations, less attention has been dedicated to the “selective” form it can take. The present study tested different aspects of Cortina’s theory of selective incivility as a “modern” manifestation of discrimination. This study extends the theory by being the first to investigate uncivil experiences Indigenous employees might be confronted with in organizations and how it might lead to experiencing higher symptoms of psychological distress. To do so, we collected data from 6706 employees working in a large Canadian public organization who were asked to complete measures of psychological distress and incivility from co-workers and supervisors. According to analyses of parallel mediation, women were less likely to report uncivil treatment from co-workers and direct supervisors than men. Evidence of moderated mediation also emerged, with target gender and Indigenous identity interacting to predict uncivil experiences, such that Indigenous women reported worse treatment from direct supervisors (b = .92, p = .03, ΔR2 = .0007), impacting their level of psychological distress (index = -.21, 95% CI [.01, .41]). Overall, our findings suggest that incivility does not work consistently against women in organizations and that intersectionality plays a role in predicting identity-based mistreatment. Our results also suggest that practitioners should consider an intersectional approach when implementing policies and interventions regarding identity-based mistreatment.

Prevalence of helmintic infections in Brazilian Maxakali indigenous: a repeated cross-sectional design

Abstract

Background

The prevalence of intestinal parasites is known to be high among Amerindian populations; further, there are serious problems in the healthcare of these populations in Brazil. The Maxakali, located in the northeastern region of Minas Gerais, Brazil, is an indigenous group that still preserves many of its cultural aspects. This study aimed to compare the positivity rate of schistosomiasis and soil-transmitted helminths in this ethnic group in epidemiological surveys conducted in 1972 and 2014.

Methods

Stool parasitological examinations were performed by the Kato-Katz technique during both periods in this population. In 2014, the parasitological diagnosis was also realized with the TF-Test® technique.

Results

In 1972, 270 inhabitants were examined. The positivity rates were 67.4% for Schistosoma mansoni, 72.9% for hookworms, 43.7% for Ascaris lumbricoides, and 23.7% for Trichuris trichiura. In 2014, 545 individuals were examined, and the positivity rates obtained were 45.7% for S. mansoni, 22.8% for hookworms, 0.6% for A. lumbricoides, and 2.8% for T. trichiura.

Conclusions

The comparison of the parasitological surveys conducted in 1972 and 2014, indicates that the indigenous Maxakali remained neglected by the health and indigenous protection authorities during these four decades. The infection rate observed in 2014 for schistosomiasis and hookworm remains high, considering the current epidemiological view of these diseases in the Brazilian population.