3,718 research outputs found
Fine structures of solar radio type III bursts and their possible relationship with coronal density turbulence
Solar radio type III bursts are believed to be the most sensitive signatures of near-relativistic electron beam propagation in the corona. A solar radio type IIIb-III pair burst with fine frequency structures, observed by the Low Frequency Array (LOFAR) with high temporal (~10 ms) and spectral (12.5 kHz) resolutions at 30â80 MHz, is presented. The observations show that the type III burst consists of many striae, which have a frequency scale of about 0.1 MHz in both the fundamental (plasma) and the harmonic (double plasma) emission. We investigate the effects of background density fluctuations based on the observation of striae structure to estimate the density perturbation in the solar corona. It is found that the spectral index of the density fluctuation spectrum is about â1.7, and the characteristic spatial scale of the density perturbation is around 700 km. This spectral index is very close to a Kolmogorov turbulence spectral index of â5/3, consistent with a turbulent cascade. This fact indicates that the coronal turbulence may play the important role of modulating the time structures of solar radio type III bursts, and the fine structure of radio type III bursts could provide a useful and unique tool to diagnose the turbulence in the solar corona
Providing global public goods: Electoral delegation and cooperation
This paper experimentally examines the effect of electoral delegation on providing global public goods shared by several groups. Each group elects a delegate who can freely decide on each group memberâs contribution (including the contribution of herself) to the global public good. Our results show that people mostly vote for delegates who assign equal contributions for every group member. However, in contrast to standard theoretical predictions, unequal contributions across groups drive cooperation down over time, and it decreases efficiency by almost 50% compared to the benchmark. This pattern is not driven by delegates trying to exploit their fellow group members, as indicated by the theory â quite to the opposite, other-regarding preferences and a re-election incentives guarantee that delegates assign equal contributions for all group members. Since the source of the resulting inefficiency is the polycentric nature of global public goods provision together with other-regarding preferences, we use the term Pinefficiency to describe our finding
Consumption and savings of migrants in China â social cohesion perspective
Boosting domestic demand is the task of Chinaâs sustainable economic development, and in particular, China has become an
important global consumer market and the savings patterns
should be more cohesive and without discriminations. Using data
of China Migrants Dynamic Survey, the paper provides new evidence on internal migrantsâ savings in China from the perspective
of homeownership and family migration. We find that migrantsâ
savings are 5.25â6.60 percentage points higher than hukou population even when controlling for working, social status, and social
insurance coverage which means the migrant will save
1019.88â1647.10 yuan in 2010 price more monthly. Furthermore,
we discover housing could partly explain the saving gap, while
when we take remittance and family migration into account, the
saving rate differences between migrants and hukou population
disappears, which means migrants may save to consume when
they go back to their hometown with their family members
instead of consuming later in the resident cities. The research is
carried out taking into account the objectives of social cohesion
policy identified at national and international level and their
involvement in consumption and saving processes. Our empirical
results reveal that homeownership, remittance motive and family
migration play important roles in shaping saving behaviour
of migrants
YOIO: You Only Iterate Once by mining and fusing multiple necessary global information in the optical flow estimation
Occlusions pose a significant challenge to optical flow algorithms that even
rely on global evidences. We consider an occluded point to be one that is
imaged in the reference frame but not in the next. Estimating the motion of
these points is extremely difficult, particularly in the two-frame setting.
Previous work only used the current frame as the only input, which could not
guarantee providing correct global reference information for occluded points,
and had problems such as long calculation time and poor accuracy in predicting
optical flow at occluded points. To enable both high accuracy and efficiency,
We fully mine and utilize the spatiotemporal information provided by the frame
pair, design a loopback judgment algorithm to ensure that correct global
reference information is obtained, mine multiple necessary global information,
and design an efficient refinement module that fuses these global information.
Specifically, we propose a YOIO framework, which consists of three main
components: an initial flow estimator, a multiple global information extraction
module, and a unified refinement module. We demonstrate that optical flow
estimates in the occluded regions can be significantly improved in only one
iteration without damaging the performance in non-occluded regions. Compared
with GMA, the optical flow prediction accuracy of this method in the occluded
area is improved by more than 10%, and the occ_out area exceeds 15%, while the
calculation time is 27% shorter. This approach, running up to 18.9fps with
436*1024 image resolution, obtains new state-of-the-art results on the
challenging Sintel dataset among all published and unpublished approaches that
can run in real-time, suggesting a new paradigm for accurate and efficient
optical flow estimation.Comment: arXiv admin note: text overlap with arXiv:2104.02409 by other author
Synthesis of Porous NiO and ZnO Submicro- and Nanofibers from Electrospun Polymer Fiber Templates
Porous nickel oxide (NiO) and zinc oxide (ZnO) submicro- and nanofibers were synthesized by impregnating electrospun polyacrylonitrile (PAN) fiber templates with corresponding metal nitrate aqueous solutions and subsequent calcination. The diameter of the NiO and ZnO fibers was closely related to that of the template fibers and larger diameters were obtained when using the template fibers with larger diameter. SEM results showed that the NiO and ZnO fibers have a large amount of pores with diameters ranging from 5 nm to 20 nm and 50 nm to 100 nm, respectively. Energy dispersive X-ray (EDX) spectra and X-ray diffraction (XRD) patterns testified that the obtained materials were NiO and ZnO with high purity
Pre-eclampsia training needs of midwives in a Ghanaian tertiary hospital: A cross-sectional study
Aim: This study aimed to assess the specific clinical and non-clinical training needs of midwives and determine their preferred approach to enhancing performance. Background: Pre-eclampsia remains one of the leading causes of maternal deaths in low and middle-income countries. Pre-eclampsia-related deaths may be due to reduced midwifery knowledge and inadequate management. Therefore, a training needs assessment is vital in identifying gaps in practice, especially, in poorly resourced settings for maximal use of training resources. Design: A hospital-based cross-sectional study. Setting: The largest tertiary hospital in Ghana. Methods: An online version of the validated WHO Hennessy-Hicks Training Needs Analysis questionnaire was used to assess midwivesâ training needs on the management of pre-eclampsia. The tool has good psychometric properties and was used to assess 1) midwivesâ confidence in performing tasks, 2) the importance of the task to their role and 3) their preferred performance improvement approach. Data analysis adhered to the guidelines specified in the Hennessy-Hicks Training Needs Analysis Questionnaire and the priority training requirements of the midwives were assessed through descriptive statistics and a series of independent t-tests. Results: Among the 250 midwives who responded, most possessed 1â5 years of experience (74.7 %). All 28 tasks were viewed by midwives as essential responsibilities in pre-eclampsia management. Midwives had the greatest need for training in research/audit and clinical skills domains respectively (p \u3c 0.001, 95 % confidence interval: 1.08â1.47, Cohen\u27s-D = 1.27; and p \u3c 0.001, 95 % confidence interval: 0.69â1.06, Cohen\u27s-D = 0.87). The foremost primary training necessity, as recognised by midwives, was undertaking health promotion activities, including antenatal health education (MD= 0.43, 95 % confidence interval: 0.29â0.57). Training courses were identified as the preferred approach to address training needs and improve overall proficiency. Conclusion: Midwives in Ghana require comprehensive training covering research and clinical-based competencies to improve pre-eclampsia management. Considering the pivotal role of Ghanaian midwives in safeguarding maternal well-being, there is a compelling need to enhance the calibre of midwifery services. These findings can guide stakeholders in countries with comparable healthcare contexts in creating effective, resource-efficient training programs that avoid counterproductivity, ultimately supporting national initiatives to enhance pre-eclampsia management and the quality of care
A qualitative document analysis of policies influencing preeclampsia management by midwives in Ghana
Background: Preeclampsia is a global issue that causes significant morbidity and mortality in low- and middle-income countries (LMICs). The care women with preeclampsia receive in LMICs is below the standard experienced by women in westernised countries due to multiple interacting factors. A review of policy factors influencing the management of preeclampsia in Ghana is needed. Aim: This study focuses on the midwife\u27s role and scope of practice concerning preeclampsia management. The study aimed to explore the congruence between Ghanaian preeclampsia guidelines and international best practice recommendations for midwifery practice. The study also aimed to describe how recommendations are incorporated into Ghanaian guidelines. Method/design: This study was a qualitative document analysis of national and tertiary hospital policies related to midwivesâ scope of practice in Ghana. Altheide\u27s five-step process (sampling, data collection, data coding and organisation, data analysis and report) was used to systematically source and analyse the content of written documents. Results: The findings illustrated several recommendation shortcomings in Ghanaian documents at the national and tertiary hospital levels. The content of Ghanaian preeclampsia management guidelines was not comprehensive, contained conflicting information, and was not backed by research evidence. The standards of practice for midwives were consistent at both the national and tertiary hospital levels. Midwives had limited roles in detection, management, stabilisation, and referral of women with preeclampsia. Conclusion: Uniform guidelines incorporating international recommendations are urgently needed to improve multi-professional collaboration, solidify midwivesâ roles, and optimise maternal and fetal outcomes
Midwivesâ experiences of providing pre-eclampsia care in a low- and middle-income country â A qualitative study
Problem: Like other low- and middle-income countries, Ghana has high maternal mortality stemming from pre-eclampsia. Ghanaian midwives are frontline service providers of emergency care in obstetric complications and have the greatest potential to maximise pre-eclampsia outcomes. Little is known about the potential barriers and challenges to midwives\u27 capacity to provide quality care in pre-eclampsia in Ghana. Therefore, we aimed to explore and gain insights into midwivesâ experiences of pre-eclampsia care including their knowledge, skills, and psychological aspects such as midwives\u27 resilience. Background: There is a rising global incidence of pre-eclampsia. Quality midwifery care in inter-professional collaborative practice is crucial to reducing pre-eclampsia-related morbidity and mortality. Methods: A qualitative descriptive exploratory study. In-depth semi-structured interviews (n = 35) were performed in 2021 and analysed by thematic analysis. Findings: There were three main themes. 1) Competence and Confidence in care; midwives provided timely and appropriate care based on sound knowledge and skills; they explained how pre-eclampsia care was organised within a multidisciplinary context and described collaborative working amongst midwives for mutual learning and support. 2) Emotional concerns and empathy; midwivesâ described fulfillment in achieving positive pre-eclampsia outcomes. In contrast, maternal loss was distressing and traumatic. 3) Call for improved care resources for pre-eclampsia; midwives recommended expansion of continuing professional development opportunities, appropriate infrastructure, resources, tailored public education, and a review of pre-service education to support their participation in pre-eclampsia care. Conclusion: To improve the quality of care in pre-eclampsia, midwives should be capacitated, systems should promptly address barriers, and prioritise midwivesâ emotional well-being
- âŚ