32584 research outputs found
Sort by
Photoinduced Charge Injection from Shallow Point Defects in Diamond into Water
Get PDFThanks to its low or negative surface electron affinity and chemical inertness, diamond is attracting broad attention as a source material of solvated electrons produced by optical excitation of the solid-liquid interface. Unfortunately, its wide bandgap typically imposes the use of wavelengths in the ultraviolet range, hence complicating practical applications. Here, we probe the photocurrent response of water surrounded by single-crystal diamond surfaces engineered to host shallow nitrogen-vacancy (NV) centers. We observe clear signatures of diamond-induced photocurrent generation throughout the visible range and for wavelengths reaching up to 594 nm. Experiments as a function of laser power suggest that NV centers and other coexisting defects─likely in the form of surface traps─contribute to carrier injection, though we find that NVs dominate the system response in the limit of high illumination intensities. Given our growing understanding of near-surface NV centers and adjacent point defects, these results open new perspectives in the application of diamond-liquid interfaces to photocarrier-initiated chemical and spin processes in fluids
Review of three southwestern Indian Ocean species of Rhinobatos (Rhinopristiformes: Rhinobatidae)
Get PDFThe shark-like rays (Rhinopristiformes) are among the most threatened species of cartilaginous fishes. The guitarfishes (Rhinobatidae) are one of 5 families in the order, with 62% of species assessed as Vulnerable or higher by the International Union for the Conservation of Nature (IUCN). Species-specific fisheries and conservation efforts have been limited, however, due to unresolved taxonomic issues and poor species descriptions. Presently, there are 3 described species of Rhinobatos from the southwestern Indian Ocean (SWIO): R. austini, R. holcorhynchus, and R. nudidorsalis. These 3 species have been mistaken for one another and are assessed as Data Deficient by the IUCN. Since the descriptions of R. austini and R. nudidorsalis, additional specimens have become available and a rediagnosis of these 3 species is required to clarify their taxonomic status. In the present study, morphometrics from 4 additional congener Indian Ocean species of Rhinobatos assessed by the IUCN were analyzed and serve as comparative material. In addition to a traditional morphological analysis, morphometrics from all 7 species were analyzed using a principal component analysis (PCA) and linear discriminant analysis (LDA). Results show distinct clusters for the SWIO Rhinobatos and indicate the nasal region is effective in differentiating species. R. austini, R. holcorhynchus, and R. nudidorsalis are confirmed as distinct species and are rediagnosed based on new material. These rediagnoses provide taxonomic clarity for SWIO Rhinobatos and will aid in species-specific identification, leading to improvements in conservation and fisheries monitoring and management
Workplace support for physicians during the COVID-19 Pandemic: Did it affect burnout?
Get PDFBackground: A concern before 2020, physician burnout worsened during the COVID-19 pandemic. Little empirical data are available on pandemic workplace support interventions or their influence on burnout. We surveyed a national sample of frontline physicians on burnout and workplace support during the pandemic. Methods: We surveyed a stratified random sample of 12,833 US physicians most likely to care for adult COVID-19 patients from the comprehensive AMA Physician Professional Data ™ file. The sample included 6722 primary care physicians (3331 family physicians, 3391 internists), 880 hospitalists, 1783 critical care physicians (894 critical care physicians, 889 pulmonary intensivists), 2548 emergency medicine physicians, and 900 infectious disease physicians. The emailed survey elicited physicians’ perceptions of organizational interventions to provide workplace support and/or to address burnout. Burnout was assessed with the Professional Fulfillment Index Burnout Composite scale (PFI-BC). Proportional specialty representation and response bias were addressed by survey weighting. Logistic regression assessed the association of physician characteristics and workplace interventions with burnout. Results: After weighting, respondents were representative of the total sample. Overall physician burnout was 45.4%, significantly higher than in our previous survey. Open-ended responses mentioned that staffing shortages (physician, nursing, and other staff) combined with the increased volume, complexity, and acuity of patients during the pandemic increased job demands. The most frequent workplace support interventions were direct pandemic control measures (increased access to personal protective equipment, 70.0%); improved telehealth functionality (43.4%); and individual resiliency tools (yoga, meditation, 30.7%). Respondents placed highest priority on workplace interventions to increase financial support and increase nursing and clinician staffing. Factors significantly associated with lower odds of burnout were practicing critical care (compared with emergency medicine) OR 0.33 (95% CI 0.12 – 0.93), improved telehealth functionality OR 0.47 (95% CI 0.23 – 0.97) and being in practice for 11 years or longer OR 0.44 (95% CI 0.19–0.99). Conclusions: Burnout across frontline specialties increased during the pandemic. Physician respondents focused on inadequate staffing in the context of caring for more and sicker patients, combined with the lack of administrative efforts to mitigate problems. Burnout mitigation requires system-level interventions beyond individual-focused stress reduction programs to improve staffing, increase compensation, and build effective teams
Academic Librarians with Invisible Disabilities Carry an Invisible Workload that Limits their Career Potential
Get PDF
The Indirect Benefits of a Transit Apprenticeship and its Potential Value as a Flexible Postsecondary Pathway
Get PDFThe transit sector has begun to embrace apprenticeships as a worthwhile training model. Apprenticeships may also address young people’s interest in career advancement opportunities, an additional benefit to the transit sector as it replaces an aging workforce and resolves other recruitment challenges. Apprenticeships that emphasize both technical and soft skills invest in career advancement by offering employees the chance to develop “cross-cutting competencies.” A highly developed model of this approach is found in the Santa Clara Valley Transportation Authority Joint Workforce Initiative (JWI), which formally recognizes skills acquisition with accredited certificates. Further development of this model would find support in initiatives to restructure postsecondary education in ways that better integrate non-degree and degree programs. Those efforts are gaining strength in response to persistent non-completion rates and declining college wealth premiums. This study contextualizes the JWI’s strengths within the revival of non-degree credentials fueled by efforts like the California Guided Pathways Program. It identifies the JWI as a good candidate for pathways that lead to a degree. Drawing on guidelines for connecting job training with degree programs, the study details the importance of affordability, portability, and articulation and outlines how these features could be further developed in the JWI
Improving the Diversity and Fairness in Job Recommendations using the Stable Matching Algorithm
No full textIn today’s competitive job market, recommendation systems are essential for con- necting job seekers with suitable opportunities. However, traditional recommendation
models, such as collaborative and content-based filtering face challenges in ensuring diversity and fairness. This results in low diversity and high congestion around popular job listings which refers to the problem where a few jobs are recommended to large numbers of users as well as imbalanced job exposure. These drawbacks lower the satisfaction for job applicants and reduce the employers’ ability to reach a broader pool of candidates. In this research we address these challenges by introducing the Gale-Shapley algorithm or stable matching algorithm into our job recommendation
system. Our approach focuses on balancing job exposure and aligning the prefer- ences of job seekers and employers more effectively. Our method improves upon
the conventional models by not only reducing congestion in high-demand roles but also increasing diversity and fairness. Through our experiments on a job application dataset, we demonstrate that the stable matching approach improves metrics such as congestion, Gini index, and coverage by a factor of 2 consistently across job domains and varying levels of user-job interactions. We achieve this without compromising accuracy and precision. This shows that the stable matching approach reduces job application competition and supports a more balanced outcome for job seekers. Our results underscore the potential of stable matching-based systems to enhance the fairness and effectiveness of job recommendation systems
A Top Model of Urban Residents’ Subjective Well-Being in China
Get PDFPast research on subjective well-being (SWB) in Western society and China has revealed various contributing factors. This study conducted a series of interviews with Chinese urban residents to systematically analyze those factors based on Bronfenbrenner’s Ecological System Theory. The results revealed that 5 layers, 23 factors, and 55 elements, many of which had distinct Chinese characteristics, contributed to Chinese urban residents’ SWB. The Top Model of SWB, visualized as a spinning top or gyroscope, showcased the interdependent layers of factors impacting Chinese urban residents’ SWB. At its vertical axis is a time dimension as residents often reflect on factors by comparing their present situation with the past and the future. Discussion regarding each layer, the primary factors that comprise each layer, links between the layers, and the impact of a time dimension was included to substantiate the proposed model. The discussions focus on the study’s contribution to SWB literature, public policy-making, and future research on urban Chinese residents’ SWB
Next steps for assessing ocean iron fertilization for marine carbon dioxide removal
Get PDFThere are many potential approaches to marine carbon dioxide removal (mCDR), of which ocean iron fertilization (OIF) has the longest history of study. However, OIF studies to date were not primarily designed to quantify the durability of carbon (C) storage, nor how wise OIF might be as an mCDR approach. To quantify C sequestration, we introduce a metric called the “centennial tonne,” defined as 1,000 kg of C isolated from atmospheric contact for on average at least 100 years. We present the activities needed to assess OIF from a scientific and technological perspective, and additionally, how it might be responsibly studied and potentially deployed. The five activities include: field studies in the Northeast Pacific; improved modeling for field studies, data assimilation and predictions at larger scales; improvements in monitoring, reporting and verification (MRV) for C, and also MRV for tracking ecological and environmental impacts; and developing new iron sources and their delivery, to increase efficiencies and reduce costs. The fifth activity is to understand whether public and community support exists for OIF, and what governance structures might support further research and possible deployment of OIF. This article is written by a multidisciplinary experts group called Exploring Ocean Iron Solutions (ExOIS) that is organized around a responsible code of conduct. Of the mCDR approaches, OIF has the potential to be low cost, scalable, and rapidly deployable. Reducing CO2 emissions must lead the way, but there is also an urgency to decide under what conditions and whether OIF might be deployed or not