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Eguchi-Hanson harmonic spinors revisited
Get PDFWe revisit the problem of determining the zero modes of the Dirac operator on the Eguchi-Hanson space. It is well known that there are no normalisable zero modes, but such zero modes do appear when the Dirac operator is twisted by a U (1) connection with L 2 normalisable curvature. The main novelty of our treatment is that we use the established formalism of spin-c spinors as complex differential forms, which makes the required calculations remarkably straightforward. In particular, to compute the Dirac operator we never need to compute the spin connection. As a result, we are able to reproduce the known normalisable zero modes of the twisted Eguchi-Hanson Dirac operator by relatively simple computations. We also collect various different descriptions of the Eguchi-Hanson space, including its construction as a hyperkähler quotient of C 4 with the flat metric. The latter illustrates the geometric origin of the connection with L 2 curvature used to twist the Dirac operator. To illustrate the power of the formalism developed, we generalise the results to the case of Dirac zero modes on the Ricci-flat Kähler manifolds obtained by applying Calabi's construction to the canonical bundle of C P n
How perceived income inequality affects charitable giving and volunteering: assessing four mechanisms
Get PDFPublic concerns about economic inequality are large and growing, and they have been shown to affect people's charitable giving and volunteering. While empirical literature addresses this issue, it provides little evidence on the underlying mechanisms linking inequality and civic engagement. Scholars from different disciplines have proposed numerous hypotheses about these mechanisms, with the social disintegration, conflict, relative power, and unmet needs hypotheses among the most frequently suggested. In this study, we apply mediation analysis to survey data from Austria and Germany (N = 1,691) to assess which of these mechanisms help explain the relationship. Our results support the social disintegration and unmet needs hypotheses: individuals who completely agree that income inequality is too high are slightly less likely to give to charity (volunteer) due to the indirect relationship through generalised social trust and substantially more likely to give to charity (volunteer) due to the indirect relationship through impure altruism compared to those who completely disagree that income inequality is too high. These findings imply that multiple mechanisms work in opposing directions. Our study provides an important step in theory development in this field and serves as a basis for future experimental studies
Cultivating inclusive remote workplaces: A serial mediation analysis of employee outcomes
Get PDFThe transformation of traditional workplace arrangements has introduced unique challenges for fostering inclusion and retaining organizational identification among remote workers. This study examines how inclusion climate influences employee outcomes in remote work settings-a context that has become increasingly prevalent yet remains understudied in terms of inclusion dynamics. Through a two-wave study involving a sample of 156 remote workers, we find that organizational identification mediates the relationship between perceived inclusion climate and well-being. Furthermore, we demonstrate that subjective well-being mediates the relationship between organizational identification and key employee outcomes, namely job satisfaction, organizational citizenship behaviors, and employee retaliation. Importantly, our results reveal a serial mediation effect, where organizational identification and subjective well-being sequentially mediate the relationship between perceived inclusion climate and both job satisfaction and employee retaliation. These findings contribute to our understanding of the mechanisms through which inclusion influences remote workers' well-being and behavior
Enhancing Order Fulfilment Services on Social Livestreaming: An Evaluation of Logistics Experience
No full textIn the realm of social livestreaming commerce, the enhanced interactivity relative to traditional e-commerce models induces considerable fluctuations in real-time orders. This variability necessitates the development of faster, more precise, and seamless order fulfilment processes to elevate customer satisfaction and foster long-term loyalty. As a leading platform in the social livestreaming commerce sector, TikTok has implemented a merchant experience rating system, which features the Logistics Experience Score (LES) to evaluate the logistics performance of its merchants. This study aims to explore the ways in which improving the order fulfilment processes can augment the logistics performance of merchants, with a particular focus on the LES as a primary metric. The research employed a two-phase design, consisting initially of surveys (N1 = 421) and subsequently, follow-up semi-structured interviews (N2 = 21) with TikTok merchants. The outcomes from the first phase underscore the pivotal role of IT infrastructure in enhancing the 'order receipt' and 'pick and pack' stages. Concurrently, Logistics Service Quality (LSQ) profoundly influences the 'ship and transport' and 'order delivery' stages. Most notably, the 'ship and transport' sub-process has emerged as a critical determinant impacting the LES, thereby underscoring its significance in shaping customer perceptions of logistics services. Findings from the second phase indicate that substantial improvements in the LES can be achieved through strategic investments in IT infrastructure and forging partnerships with reliable logistics providers. Such enhancements aim to increase the speed, efficiency, and reliability of shipping and transportation. Through these findings, this research contributes to the broader understanding of order fulfilment within the context of social livestreaming commerce, providing both theoretical and empirical insights that are valuable for merchants active in this field
A closer look at Witt rings for forms of higher degree
Get PDFWitt rings for nondegenerate forms ϕ of degree d over a field of characteristic 0 or greater than d were defined by Harrison and Pareigis in 1988. We revisit and discuss their definition in light of recent developments. We classify the H-spaces employed in their definition, demonstrate the restrictions on the structure imposed on Witt rings due to a Krull-Schmidt Theorem for forms of higher degree, and propose to define Witt rings of diagonal forms of degree d. We investigate some special cases; and define two new types of Witt rings for nondegenerate forms ϕ of degree d
Social capital, corporate governance, and earnings management: Cross-country evidence
No full textThis study investigates the impact of social capital on earnings management and the moderating role of corporate governance in shaping that relationship. We explore how the interaction between social capital and other mechanisms, namely culture and formal institutions, affects earnings management, based on the concept that corporate governance can strengthen the impact of social capital on earnings management by reinforcing ethical norms and accountability. Using data from 14 countries, we present evidence that social capital has an effect on earnings management beyond the influence of cultural attributes. Moreover, the impact of social capital is particularly significant in firms with low corporate governance quality. Further analysis shows that the influence of social capital on earnings management is heightened in countries exhibiting low levels of individualism, power distance, and indulgence, and in countries with a code law system, lower ownership concentration, and higher disclosure quality. Our study contributes to the literature by demonstrating, using a crosscountry context, that social capital constrains earnings management practices. It also highlights the additional impact of social capital beyond cultural dimensions, emphasizing its distinct role as a norm-enforcing mechanism with sanctions, separate from attributes such as individualism or uncertainty avoidance. Furthermore, the study offers new insights into the interplay between social capital and corporate governance in shaping corporate financial practices
Mannitol for cerebral oedema after acute intracerebral haemorrhage (MACE-ICH): protocol for a prospective, randomised, open-label, blinded-endpoint phase IIb trial
Get PDFBackground Acute intracerebral haemorrhage (ICH) is devastating with a 1 month mortality rate of ~40%. Cerebral oedema can complicate acute ICH and is associated with poor outcome. In patients with large ICH, the accompanying swelling increases mass effect and causes brain herniation. Mannitol, an osmotic diuretic, is used to treat cerebral oedema after traumatic brain injury, but its safety and efficacy in ICH is unclear. We aim to assess the feasibility of a phase II randomised, controlled trial of mannitol in patients with ICH with, or at risk of, cerebral oedema to inform a definitive trial. Methods The mannitol for cerebral oedema after acute intracerebral haemorrhage trial (MACE-ICH) aims to include 45 ICH participants from 10 UK sites with estimated largest diameter of haematoma volume >2 cm, presenting within 72 hours of onset with, or at risk of, cerebral oedema (limited Glasgow Coma Scale (GCS)8) with or without mass effect. Participants will be randomised (1:1:1) to 1 g/kg 10% single-dose intravenous mannitol, 1 g/kg 10% mannitol followed by a second dose at 24 hours, or standard care alone. Outcome assessors will be masked to treatment allocation. Feasibility outcomes include proportion of patients approached being randomised, participants receiving allocated treatment, recruitment rate, treatment adherence and follow-up. Secondary outcomes include serum electrolytes and osmolality at days 1-2; change in ICH and oedema volume at day 5; number of participants who developed urinary tract infection, GCS and National Institutes of Health Stroke Scale at day 5±2; length of hospital stay, discharge destination and death up to day 28; death and death or dependency by day 180 and disability (Barthel Index), quality of life (EuroQol, 5-D) and cognition (telephone mini-mental state examination) at day 180. Ethics and dissemination MACE-ICH received ethics approval from the East Midlands-Leicester Centra
ABA-auxin cascade regulates crop root angle in response to drought
No full textEnhancing drought resistance through the manipulation of root system architecture (RSA) in crops represents a crucial strategy for addressing food insecurity challenges. Abscisic acid (ABA) plays important roles in drought tolerance; yet, its molecular mechanisms in regulating RSA, especially in cereal crops, remain unclear. In this study, we report a new mechanism whereby ABA mediates local auxin biosynthesis to regulate root gravitropic response, thereby controlling the alteration of RSA in response to drought in cereal crops. Under drought conditions, wild-type (WT) plants displayed a steep root angle compared with normal conditions, while ABA biosynthetic mutants (mhz4, mhz5, osaba1, and osaba2) showed a significantly shallower crown root angle. Gravitropic assays revealed that ABA biosynthetic mutants have reduced gravitropic responses compared with WT plants. Hormone profiling analysis indicated that the mhz5 mutant has reduced auxin levels in root tips, and exogenous auxin (naphthaleneacetic acid [NAA]) application restored its root gravitropic defects. Consistently, auxin reporter analysis in mhz5 showed a reduced auxin gradient formation in root epidermis during gravitropic bending response compared with WT plants. Furthermore, NAA, rather than ABA, was able to rescue the compromised gravitropic response in the auxin biosynthetic mutant mhz10-1/tryptophan amino transferase2 (ostar2). Additionally, the maize ABA biosynthetic mutant viviparous5 (vp5) also showed gravitropic defects and a shallower seminal root angle than WT plants, which were restored by external auxin treatment. Collectively, we suggest that ABA-induced auxin synthesis governs the root gravitropic machinery, thereby influencing root angle in rice, maize, and possibly other cereal crops
Teaching robots to weld by leveraging human expertise
Get PDFRobotic welding systems are pivotal in various manufacturing sectors, such as aerospace, construction, automotive, and maritime industries, due to their ability to operate in challenging environments with fewer physical constraints compared to human welders. However, their lack of process knowledge and adaptability necessitates heavy reliance on experienced technicians for process planning. To mitigate these challenges, a novel robotic welding system is proposed, focusing on learning from manual operations. In the proposed approach, proficient welders execute basic tasks, such as welding simple lines or arcs, while their actions are recorded using an operation tracking system. Then key welding parameters, such as torch travelling speed, welding arc length, welding angle, welding current, and wire feeding rate, are extracted and stored in a skill library. New welding tasks are segmented into the elements of the library. These are matched with archived parameters to plan the process for the robotic welding system, effectively transferring welding expertise to the automated system. Experiments have been conducted to verify the system. A skilled welder was asked to weld linear and arc-shaped grooves on stainless steel workpieces, while the welder’s skills were tracked, extracted, and stored digitally. These skills were further used to plan the robotic welding system to execute new complex tasks, such as polynomial curves. Welding results from the robot show a quality that is on par with that of a skilled welder
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