Comparative analysis of cytokine profiles of glaucomatous tears and aqueous humour reveals potential biomarkers for trabeculectomy complications

L

Performance of wide-area power system stabilizers during major system upsets: investigation and proposal of solutions

© 2021 Springer Nature Switzerland AG. This is a post-peer-review, pre-copyedit version of Benasla, M., Denaï, M., Liang, J. et al. Performance of wide-area power system stabilizers during major system upsets: investigation and proposal of solutions. Electr Eng (2021). The final authenticated version is available online https://doi.org/10.1007/s00202-020-01168-3Wide-area damping controllers (WADCs) are effective means of improving the damping of inter-area oscillations and thereby ensuring a secure operation of modern highly stressed interconnected power systems; however, their implementation costs are high. Therefore, the controller must be well configured and designed to ensure its cost-effectiveness. Several techniques have been proposed in the literature to design effective controllers and good results have been achieved. However, some important practical aspects that could potentially impact the performance of the designed controller have not been addressed or studied in sufficient detail in these previous works. One such aspect is assessing the performance of the designed controllers under major system upsets resulting in large deviations in the frequency and fluctuations in the power. These may lead to controller saturation which could negatively impact its damping performance or even cause instability. In this paper, the impact of such large upsets is investigated on several test systems via extensive small- and large-signal analyses and it is shown that, during severe transients, controller saturation may occur and persist over a long period of time, posing a potential threat to the power system stability. This paper presents a very effective solution to alleviate this problem and help design more robust WADCs. The simulation results show that the proposed solution works well and leads to improved power system stabilisers performance during transient upsets.Peer reviewedFinal Accepted Versio

Identifying Sources of Health Care Underutilization Among California’s Immigrants

Many studies show that immigrants face significant barriers in accessing health care. These barriers may be particularly pronounced for newer immigrants, who may face additional obstacles in navigating the health care system. Understanding the sources of health care disparities between recent and non-recent immigrants may allow for better design of policies and interventions to address the vulnerabilities unique to different subgroups of immigrants defined by their length of residency. This study employs descriptive analyses and multivariate logistic regression to estimate the likelihood of accessing and utilizing health care services based on immigration-related factors after controlling for predisposing, enabling, and health care need factors. We also employ a regression-based decomposition method to determine whether health care differences between recent and non-recent immigrants are statistically significant and to identify the primary drivers of healthcare differences between recent and non-recent immigrants. The findings support the hypothesis that significant disparities in health care access and utilization exist between recent and non-recent immigrants. We found that health care access and utilization differences between recent and non-recent immigrants were driven primarily by enabling resources, including limited English proficiency (LEP), insurance status, public assistance usage, and poverty level. These results indicate that not only are newer immigrants more likely to underutilize health care, but also that their underutilization is driven primarily by their lack of insurance, lack of adequate financial resources, and inability to navigate the health care system due to LEP. The results further indicate that immigrants with prolonged LEP may be less likely to have a usual source of care and more likely to report delays in obtaining medical treatments, than even recent immigrants with LEP

The self-organizing fractal theory as a universal discovery method: the phenomenon of life

A universal discovery method potentially applicable to all disciplines studying organizational phenomena has been developed. This method takes advantage of a new form of global symmetry, namely, scale-invariance of self-organizational dynamics of energy/matter at all levels of organizational hierarchy, from elementary particles through cells and organisms to the Universe as a whole. The method is based on an alternative conceptualization of physical reality postulating that the energy/matter comprising the Universe is far from equilibrium, that it exists as a flow, and that it develops via self-organization in accordance with the empirical laws of nonequilibrium thermodynamics. It is postulated that the energy/matter flowing through and comprising the Universe evolves as a multiscale, self-similar structure-process, i.e., as a self-organizing fractal. This means that certain organizational structures and processes are scale-invariant and are reproduced at all levels of the organizational hierarchy. Being a form of symmetry, scale-invariance naturally lends itself to a new discovery method that allows for the deduction of missing information by comparing scale-invariant organizational patterns across different levels of the organizational hierarchy

Human secretory immunoglobulin A may contribute to biofilm formation in the gut

It is critical, both for the host and for the long-term benefit of the bacteria that colonize the gut, that bacterial overgrowth with subsequent bacterial translocation, which may lead to sepsis and death of the host, be avoided. Secretory IgA (sIgA) is known to be a key factor in this process, agglutinating bacteria and preventing their translocation in a process termed ‘immune exclusion’. To determine whether human sIgA might facilitate the growth of normal enteric bacteria under some conditions, the growth of human enteric bacteria on cultured, fixed human epithelial cells was evaluated in the presence of sIgA or various other proteins. Human sIgA was found to facilitate biofilm formation by normal human gut flora and by Escherichia coli on cultured human epithelial cell surfaces under conditions in which non-adherent bacteria were repeatedly washed away. In addition, the presence of sIgA resulted in a 64% increase in adherence of E. coli to live cultured epithelial cells over a 45-min period. Mucin, another defence factor thought to play a key role in immune exclusion, was found to facilitate biofilm formation by E. coli. Our findings suggest that sIgA may contribute to biofilm formation in the gut