Recent Advances in Understanding Particle Acceleration Processes in Solar Flares

We review basic theoretical concepts in particle acceleration, with particular emphasis on processes likely to occur in regions of magnetic reconnection. Several new developments are discussed, including detailed studies of reconnection in three-dimensional magnetic field configurations (e.g., current sheets, collapsing traps, separatrix regions) and stochastic acceleration in a turbulent environment. Fluid, test-particle, and particle-in-cell approaches are used and results compared. While these studies show considerable promise in accounting for the various observational manifestations of solar flares, they are limited by a number of factors, mostly relating to available computational power. Not the least of these issues is the need to explicitly incorporate the electrodynamic feedback of the accelerated particles themselves on the environment in which they are accelerated. A brief prognosis for future advancement is offered.Comment: This is a chapter in a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

The Origin, Early Evolution and Predictability of Solar Eruptions

Coronal mass ejections (CMEs) were discovered in the early 1970s when space-borne coronagraphs revealed that eruptions of plasma are ejected from the Sun. Today, it is known that the Sun produces eruptive flares, filament eruptions, coronal mass ejections and failed eruptions; all thought to be due to a release of energy stored in the coronal magnetic field during its drastic reconfiguration. This review discusses the observations and physical mechanisms behind this eruptive activity, with a view to making an assessment of the current capability of forecasting these events for space weather risk and impact mitigation. Whilst a wealth of observations exist, and detailed models have been developed, there still exists a need to draw these approaches together. In particular more realistic models are encouraged in order to asses the full range of complexity of the solar atmosphere and the criteria for which an eruption is formed. From the observational side, a more detailed understanding of the role of photospheric flows and reconnection is needed in order to identify the evolutionary path that ultimately means a magnetic structure will erupt

Digital Practices by Citizens during the COVID-19 Pandemic: Findings from an International, Multi-site Study

Background:The COVID-19 pandemic brought digital practices and engagement to the forefront of society based on behaviour changes instilled by people adhering to different government mandates. Further behavioural changes included transitioning from the office to working from home, using various social media and communication platforms to maintain a level of social connectedness especially given how many people were socially isolated from friends, family members and community groups living in different types of communities such as rural, urban or city spaces. Although there is a growing body of research exploring how technology was utilized by people, little information and insight is known about the digital practices employed across different age cohorts, who are living in different physical spaces and who reside in different countries. Objective:This paper presents the findings from an international multi-site study exploring the impact of social media and the Internet on individuals' health and wellbeing in different countries during the COVID-19 pandemic. Methods: Data was collected via a series of online surveys deployed between 4th April 2020 and 30th September 2021. Respondents' age range varied between 18 and 60+ years across three regions: Europe, Asia, and North America. On exploring the associations between technology use, social connectedness, and sociodemographic factors on loneliness and wellbeing through bivariate and multivariate analyses, we observed significant differences. Results: Respondents using social media messengers and more social media apps were comparatively lonelier than those not using social media messengers and those who used zero or one social media app. Additionally, respondents who were not a member of an online community support group were lonelier than those who were a member of an online community support group. psychological wellbeing was reported to be significantly lower, and loneliness was significantly higher for people living in small towns and rural areas compared to those living in suburban and urban communities. Younger respondents (18-29 years old), single adults, unemployed, and those with lower levels of educational achievement were more likely to also experience loneliness. Conclusions: From an international and interdisciplinary perspective, policymakers and stakeholders should extend and explore interventions targeting loneliness experienced by single young adults and examine further how this may vary across geography. Study findings have implications across the fields of gerontechnology, health sciences, social sciences, media communications, computer, and information technology studies

Macroscopic description of the external and middle ear of paca (Cuniculus paca Linnaeus, 1766)

Abstract: Paca (Cuniculus paca), one of the largest rodents of the Brazilian fauna, has inherent characteristics of its species which can conribute as a new option for animal experimantation. As there is a growing demand for suitable experimental models in audiologic and otologic surgical research, the gross anatomy and ultrastructural ear of this rodent have been analyzed and described in detail. Fifteen adult pacas from the Wild Animals Sector herd of Faculdade de Ciências Agrárias e Veterinárias, Unesp-Jaboticabal, were used in this study. After anesthesia and euthanasia, we evaluated the entire composition of the external ear, registering and ddescribing the details; the temporal region was often dissected for a better view and detailing of the tympanic bulla which was removed and opened to expose the ear structures analyzed mascroscopically and ultrastructurally. The ear pinna has a triangular and concave shape with irregular ridges and sharp apex. The external auditory canal is winding in its path to the tympanic mebrane. The tympanic bulla is is on the back-bottom of the skull. The middle ear is formed by a cavity region filled with bone and membranous structures bounded by the tympanic membrane and the oval and round windows. The tympanic membrane is flat and seals the ear canal. The anatomy of the paca ear is similar to the guinea pig and from the viewpoint of experimental model has major advantages compared with the mouse ear