Light Localization and Principal Mode Propagation in Optical Fibers

The capacity of optical fiber communications has grown exponentially since its implementation decades ago. Optical fiber amplifiers, wavelength division multiplexing, and coherent communications have all enabled discontinuous growth. Space division multiplexing is proposed as the next discontinuity. Here tens of modes rather than a single mode are utilized in the transmission. Random scattering due to index fluctuations within the optical fiber cause coupling among the modal channels thereby degrading signal transmission. Principal mode transmission overcomes this limitation. Here a set of modes arrive localized at the fiber output unscattered. We review this methodology as it relates to optical communication capacity, but also as it relates to light localization. We also review the characterization of these modes both theoretically and experimentally.

Alcohol narrows physical distance between strangers

Pandemic management is likely to represent a global reality for years to come, but the roadmap for how to approach pandemic restrictions is as yet unclear. Of the restrictions enacted during COVID-19, among the more controversial surround alcohol. Like many infectious diseases, the principal mode of transmission for COVID-19 is direct respiration of droplets emitted during close social contact, and health officials warn that alcohol consumption may lead to decreased adherence to physical distancing guidelines. Governing bodies have acted to close bars before restaurants and have also specifically restricted alcohol sales, while at the same time those in the nightlife industry have labeled such actions unfounded and discriminatory. Complicating such debates is the lack of evidence on alcohol’s effects on physical distance. In the current study we employed a randomized alcohol-administration design paired with computer-vision measures, analyzing over 20,000 proximity readings derived from video to examine the effect of alcohol consumption on physical distance during social interaction. Results indicated that alcohol caused individuals to draw significantly closer to an unfamiliar interaction partner during social exchange, reducing physical proximity at a rate with potentially important implications for public health. In contrast, alcohol had no effect on physical distance with a familiar interaction partner. Findings suggest that alcohol might act to overcome a natural caution people feel towards strangers and thus promote virus transmission between previously unconnected social groups.

Benchmarking surface tension measurement method using two oscillation modes in levitated liquid metals

The Faraday forcing method in levitated liquid droplets has recently been introduced as a method for measuring surface tension using resonance. By subjecting an electrostatically levitated liquid metal droplet to a continuous, oscillatory, electric field, at a frequency nearing that of the droplet’s first principal mode of oscillation (known as mode 2), the method was previously shown to determine surface tension of materials that would be particularly difficult to process by other means, e.g., liquid metals and alloys. It also offers distinct advantages in future work involving high viscosity samples because of the continuous forcing approach. This work presents (1) a benchmarking experimental method to measure surface tension by excitation of the second principal mode of oscillation (known as mode 3) in a levitated liquid droplet and (2) a more rigorous quantification of droplet excitation using a projection method. Surface tension measurements compare favorably to literature values for Zirconium, Inconel 625, and Rhodium, using both modes 2 and 3. Thus, this new method serves as a credible, self-consistent benchmarking technique for the measurement of surface tension.

Les directives pour le traitement par surfactant exogène chez le nouveau-né

Résumé Le traitement par surfactant exogène joue un rôle essentiel dans la prise en charge des nouveau-nés atteints du syndrome de détresse respiratoire (maladie des membranes hyalines) parce qu’il améliore la survie et limite les troubles respiratoires. Puisque la ventilation non invasive est de plus en plus utilisée comme principal mode d’assistance respiratoire chez le nouveau-né prématuré à la naissance, l’administration prophylactique de surfactant n’est plus bénéfique. L’administration précoce de surfactant sous forme de traitement de rattrapage est préconisée chez les nouveau-nés dont le syndrome de détresse respiratoire s’aggrave. La stratégie qui consiste à intuber, administrer du surfactant, puis extuber (INSURE) est largement acceptée en pratique clinique, mais des méthodes non invasives plus récentes à l’aide d’un cathéter fin, d’un masque laryngé ou d’un nébuliseur sont en cours d’adoption ou d’exploration. Selon des données limitées, un traitement d’appoint par surfactant exogène pourrait être efficace pour traiter d’autres affections que le syndrome de détresse respiratoire, telles que le syndrome d’aspiration méconiale.

Toxicological Effects of Petrol, Xylene and Thinner on Mus musculus (Albino Mice)

Background: Petrol, xylene, and thinner are volatile organic compounds (VOCs), a major class of pollutants that affect the chemistry of the atmosphere and animals including man. The principal mode of contamination is via inhalation. This study aims to elucidate the effects of these compounds on bio-chemical functions in the body of the mouse, Mus musculus Methods: One hundred and twenty adult albino Mus musculus species were randomly assigned to groups (A1, A2, B1, B2, C1, C2, and D1) based on their weights (8-13g for juveniles and 15 – 21g for adults) with specific treatments. The control treatment, A1, was housed in a plastic experimental house free from the test chemical vapor while groups A2 and B1; B2 and C1; C2 and D1 were exposed to pet-rol, thinner, and xylene respectively in wooden exposure chambers for six hours daily for sixty days. Levels of oxidative stress markers (GSH, SOD, CAT, and MDA) were determined using the spectrophotometry. Results: A significant decrease in the values of GSH, activities of SOD and CAT, were observed when compared to the mice in the control experiment as daily exposure to the selected vapor increased. On the other hand, MDA levels increased significantly with increasing daily exposure to vapor from the test chemicals, when compared to the control rats. Conclusion: Based on the findings from this study, the decrease in the SOD, CAT and GSH levels are indications of toxic build up in the blood implying that exposures to these VOCs inhibit natural processes. Thus, VOCs are detrimental to human health and long-term exposure to these organic com-pounds could result in deleterious sub-lethal effects, especially to individual exposed occupationally to them

A Tale of Two Cities: Framing urban diversity as content curation in super-diverse London and Toronto

In major cities across the world policy-makers are searching for new ways to represent and govern their increasingly diverse populations. In this paper we analyse the ways in which authorities in two global cities, London and Toronto, have drawn on corporate, public management, strategies as their principal mode of diversity governance. In both we see a shift in policy making as a conscious attempt to reframe and re-imagine cities as corporate-like structures that can be conceptualised, represented, and managed through the lens of diversity management. In both cities specific representations of the city and its populations are curated to fulfil wider policy objectives. City governments present both as iconic centres of diversity, super-diversity or hyper-diversity, that embody and represent an era of progressive globalisation and new forms of contemporary cosmopolitan living. The presence of diversity is celebrated and seen a key component of ‘success agendas’. This paper is based on empirical evidence derived from a policy-oriented research project in both cities. Policy analysis and critical discourse analysis are conducted in both cities on the basis of review of policy documents at national, local and community scales, and interviews with policy makers. The paper first frames diversity as a technology of description, where we explain how diversity has become a curation strategy in public management within the framework of growing mobility of management frameworks and shifts in framing diversity in urban policies. We will then provide a comparative analysis of London and Toronto.

Human food consumption patterns concerning COVID-19 pandemic

In recent months, despite being aware of the COVID-19 pandemic, many countries faced increasing epidemic of this disease. Nearly all countries tried to decrease human-to-human contact as the principal mode of transmission of SARS-CoV-2. Other modes of transmission also need to be clarified in more depth, especially, the foodborne transmission (FBT). We assessed the effect of animal origin foods (AOF) consumption on the pandemic of COVID-19. For this purpose, we studied the relationship among 20 food supply as independent variables, and the parameter of Total Cases (TC) as dependent variable. The statistical analyses included parametric, non-parametric, frequentist, and Bayesian methods. Results showed a relationship between a group of AOF and TC. So, the role of FBT of COVID-19 should be more significant than previously thought. The possibility of Animal Origin Foodborne Transmission should be taken into more consideration. The perspective is to expand the surveillance of SARS-Cov-2 during the food production chain.

Pedagogies of Performance

The development of modern styles of elite music education played a crucial role in entrenching Werktreue as the dominant practice within classical music performance. Focusing on Germany’s first conservatory, the Leipzig conservatory, which was founded in 1843, this article analyzes how Werktreue, understood as a set of tacit competencies and sensibilities that must be learned by musicians, was produced at a single historical site. Archival documents of the institution, as well as the correspondence and writings of teachers and students like Felix Mendelssohn, William Rockstro, and Ethel Smyth, show that the central objective of musical pedagogy was the faithful interpretation of musical works. Isolated as a discrete subject of training, performing musical works also functioned as the principal mode of student assessment through semesterly examinations. To transmit the necessary skills for this paradigm of performance, pupils’ bodily capacities (Technik) and ability to understand and interpret canonic compositions (Vortrag) became essential targets of conservatory pedagogy. Ubiquitous visibility among students, and the intense competition that this visibility engendered, went hand in hand with institutionalizing styles of musical expertise that continue to this day. In exploring these developments, this article asks how the productive power of modern conservatory training contributed not only to Werktreue’s rise over a wide geography, but also to the remarkable stability with which it has pervaded performance practice across multiple generations.

Anti-Leishmanial and Immunomodulatory Effects of Epigallocat-echin 3-O-Gallate on Leishmania tropica: Apoptosis and Gene Expression Profiling

Background: Pentavalent antimonials such as meglumine antimoniate (MA, Glucantime), are the first-line treatment against leishmaniasis, but at present, they have basically lost their efficacy. This study was aimed to explore epigallocatechin 3-O-gallate (EGCG), alone or in combination with MA against Leishmania tropica stages. Methods: All experiments were carried out in triplicate using colorimetric assay, macrophage model, flow cytometry and quantitative real-time PCR. This experimental study was carried out in 2017 in Leishmaniasis Research Center, Kerman University of Medical Sciences, Kerman, Iran. Results: Promastigotes and amastigotes were more susceptible to EGCG than MA alone, but the effect was more profound when used in combination. EGCG exhibited high antioxidant level with a remarkable potential to induce apoptosis. Furthermore, the results showed that the level of gene expression pertaining to Th-1 was significantly up-regulated (P<0.001). Conclusion: EGCG demonstrated a potent anti-leishmanial effect alone and more enhanced lethal activity in combination. The principal mode of action entails the stimulation of a synergistic response and up-regulation of the immunomodulatory role towards Th-1 response against L. tropica.