Fractional graph Laplacian for image reconstruction

Image reconstruction problems, like image deblurring and computer tomography, are usually ill-posed and require regularization. A popular approach to regularization is to substitute the original problem with an optimization problem that minimizes the sum of two terms, an term and an term with . The first penalizes the distance between the measured data and the reconstructed one, the latter imposes sparsity on some features of the computed solution. In this work, we propose to use the fractional Laplacian of a properly constructed graph in the term to compute extremely accurate reconstructions of the desired images. A simple model with a fully automatic method, i.e., that does not require the tuning of any parameter, is used to construct the graph and enhanced diffusion on the graph is achieved with the use of a fractional exponent in the Laplacian operator. Since the fractional Laplacian is a global operator, i.e., its matrix representation is completely full, it cannot be formed and stored. We propose to replace it with an approximation in an appropriate Krylov subspace. We show that the algorithm is a regularization method under some reasonable assumptions. Some selected numerical examples in image deblurring and computer tomography show the performance of our proposal

SARS-CoV-2 and extracellular vesicles: An intricate interplay in pathogenesis, diagnosis and treatment

Extracellular vesicles (EVs) are widely recognized as intercellular communication mediators. Among the different biological processes, EVs play a role in viral infections, supporting virus entrance and spread into host cells and immune response evasion. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection became an urgent public health issue with significant morbidity and mortality worldwide, being responsible for the current COVID-19 pandemic. Since EVs are implicated in SARS-CoV-2 infection in a morphological and functional level, they have gained growing interest for a better understanding of SARS-CoV-2 pathogenesis and represent possible diagnostic tools to track the disease progression. Furthermore, thanks to their biocompatibility and efficient immune activation, the use of EVs may also represent a promising strategy for the development of new therapeutic strategies against COVID-19. In this review, we explore the role of EVs in viral infections with a focus on SARS-CoV-2 biology and pathogenesis, considering recent morphometric studies. The common biogenesis aspects and structural similarities between EVs and SARS-CoV-2 will be examined, offering a panoramic of their multifaceted interplay and presenting EVs as a machinery supporting the viral cycle. On the other hand, EVs may be exploited as early diagnostic biomarkers and efficient carriers for drug delivery and vaccination, and ongoing studies will be reviewed to highlight EVs as potential alternative therapeutic strategies against SARS-CoV-2 infection

Costing a Maternity Leave Cash Transfer to Support Breastfeeding Among Informally Employed Mexican Women

Background: Investing in maternity protection for working women is an important social equity mechanism. Addressing the maternity leave needs of women employed in the informal sector economy should be a priority as more than half of women in Latin America, South Asia, and sub-Saharan Africa are employed in this sector. Objective: To develop a costing methodology framework to assess the financial feasibility, at the national level, of implementing a maternity cash transfer for informally employed women. Methods: A World Bank costing methodology was adapted for estimating the financial need to establish a maternity cash transfer benefit. The methodology estimates the cash transfer’s unitary cost, the incremental coverage of the policy in terms of time, the weighted population to be covered, and the administrative costs. The 6-step methodology uses employment and sociodemographic data that are available in many countries through employment and demographic surveys and the population census. The methodology was tested with data for Mexico assuming different cash transfer unitary costs and the benefit’s time coverage. Results: The methodological framework estimated that the annual financial needs of setting up a maternity cash transfer for informally working women in Mexico ranges between US$87 million and US$280 million. Conclusions: A pragmatic methodology for assessing the costs of maternity cash transfer for informally employed women was developed. In the case of Mexico, the maternity cash transfer for women in the informal sector is financially feasible

Costos de la licencia de maternidad para apoyar la lactancia materna en Brasil, Ghana y México

Objective To develop a method to assess the cost of extending the duration of maternity leave for formally-employed women at the national level and apply it in Brazil, Ghana and Mexico. Methods We adapted a World Bank costing method into a five-step method to estimate the costs of extending the length of maternity leave mandates. Our method used the unit cost of maternity leave based on working women’s weekly wages; the number of additional weeks of maternity leave to be analysed for a given year; and the weighted population of women of reproductive and legal working age in a given country in that year. We weighted the population by the probability of having a baby that year among women in formal employment, according to individual characteristics. We applied nationally representative cross-sectional data from fertility, employment and population surveys to estimate the costs of maternity leave for mothers employed in the formal sector in Brazil, Ghana and Mexico for periods from 12 weeks up to 26 weeks, the WHO target for exclusive breastfeeding. Findings We estimated that 640 742 women in Brazil, 33 869 in Ghana and 288 655 in Mexico would require formal maternity leave annually. The median weekly cost of extending maternity leave for formally working women was purchasing power parity international dollars (PPP$) 195.07 per woman in Brazil, PPP$ 109.68 in Ghana and PPP$ 168.83 in Mexico. Conclusion Our costing method could facilitate evidence-based policy decisions across countries to improve maternity protection benefits and support breastfeeding

Cluster randomized trial assessing the effects of rapid ethical assessment on informed consent comprehension in a low-resource setting

Background Maximizing comprehension is a major challenge for informed consent processes in low-literacy and resource-limited settings. Application of rapid qualitative assessments to improve the informed consent process is increasingly considered useful. This study assessed the effects of Rapid Ethical Assessment (REA) on comprehension, retention and quality of the informed consent process. Methods A cluster randomized trial was conducted among participants of HPV sero-prevalence study in two districts of Northern Ethiopia, in 2013. A total of 300 study participants, 150 in the intervention and 150 in the control group, were included in the study. For the intervention group, the informed consent process was designed with further revisions based on REA findings. Informed consent comprehension levels and quality of the consent process were measured using the Modular Informed Consent Comprehension Assessment (MICCA) and Quality of Informed Consent (QuIC) process assessment tools, respectively. Result Study recruitment rates were 88.7 % and 80.7 % (p = 0.05), while study retention rates were 85.7 % and 70.3 % (p < 0.005) for the intervention and control groups respectively. Overall, the mean informed consent comprehension scores for the intervention and control groups were 73.1 % and 45.2 %, respectively, with a mean difference in comprehension score of 27.9 % (95 % CI 24.0 % - 33.4 %; p < 0.001,). Mean scores for quality of informed consent for the intervention and control groups were 89.1 % and 78.5 %, respectively, with a mean difference of 10.5 % (95 % CI 6.8 -14.2 %; p < 0.001). Conclusion Levels of informed consent comprehension, quality of the consent process, study recruitment and retention rates were significantly improved in the intervention group. We recommend REA as a potential modality to improve informed consent comprehension and quality of informed consent process in low resource settings

Effect of dietary Acrocomia aculeata kernel oil rich in medium chain fatty acids on type 2 diabetic rats.

This study evaluated the effects of dietaries formulated with kernel oil of Acrocomia aculeata (AKO), rich in medium chain fatty acids (MCFA), as partial substitute of carbohydrate calories upon blood glucose, lipid profile, insulin secretion and insulin sensitivity in diabetic rats. Overall, the dietary with any AKO dose reduced hyperglycemia, ameliorated insulin secretion, lowered insulin resistance by model HOMA-IR and HOMA-Beta and augmented pancreatic beta cells functionality, restored the number of pancreatic Beta-cell in the diabetic rats and increased it in the non-diabetic rats. In addition, AKO fed rats showed reducing triglycerides, lower density lipoprotein-cholesterol and increasing high density lipoprotein-cholesterol levels, and improved hepatic function markers. Those findings suggest AKO was effective to ameliorate the health of diabetic rats.On-line first