A model for the onset of oscillations near the stopping angle in an inclined granular flow

We propose an explanation for the onset of oscillations seen in numerical simulations of dense, inclined flows of inelastic, frictional spheres. It is based on a phase transition between disordered and ordered collisional states that may be interrupted by the formation of force chains. Low frequency oscillations between ordered and disordered states take place over weakly bumpy bases; higher-frequency oscillations over strongly bumpy bases involve the formation of particle chains that extend to the base and interrupt the phase change. The predicted frequency and amplitude of the oscillations induced by the unstable part of the equation of state are similar to those seen in the simulations and they depend upon the contact stiffness in the same way. Such oscillations could be the source of sound produced by flowing sand

Interview with Patrick J. Powers

Born on September 3, 1939 in Evergreen Park, Illinois, Patrick J. Powers initially grew up on the south side of Chicago through his elementary school years, and then lived in Summit, New Jersey with his family when his father was transferred to New York. Unlike his father, a business executive who had a successful career at the Bell Systems and AT&T, Pat took a strong interest in philosophy and enrolled in Villanova University in Philadelphia, PA for his undergraduate study. However, it was a study abroad experience at Collegio Internatiozale de S. Monica in Roma, Italy in the 1960s that made him decide to pursue a calling in theology. Accordingly, Powers earned his MA in Religious Education from Augustinian College in Washington, DC in 1967, another MA in Philosophy from Villanova in 1972, and his PhD in Phenomenology from Duquesne University in Pittsburgh, PA in 1978. Before moving to Central Florida, Powers taught Religion and Latin at Tolentine High School in Bronx, NY (1964-68), worked as the Assistant Chaplain at Villanova (1968-72), and served as the Director of Campus Ministry at Trinity College in Washington, DC (1976-80). In 1980, Pat became the Director of Catholic Campus Ministry at University of Central Florida, a position he held for several years. Afterwards, he worked as the Executive Director of the Christian Service Center for Central Florida, which administered multiple community programs such as daily breads for homeless, family emergency services, and marriage and therapy. On June 1, 1993, Powers was appointed by President Rita Bornstein as the Dean of the Knowles Memorial Chapel and Chaplain of the College. At Rollins, instead of Dean Powers, Pat was fondly called DP by students. He worked closely with many campus organizations such as Intervarsity, Black Student Union, Newman Club, and Hillel to sustain Rollins’ rich tradition in liberal arts education and institutional commitment to community and service learning. He also collaborated with people of different faiths and promoted chapel programs such as Candlewish and Christmas Vespers. Besides his work as campus minister, Pat also frequently taught courses in RCC (Rollins Conference Course), Hamilton Holt School and Master of Liberal Studies. In 2014, after more than two decades of service, Powers announced his retirement from Rollins College. In this oral history interview conducted by Rev. Katrina Jenkins on February 1, 2021, Powers reflected his professional career working with students, faculty, staff and administrators on various chapel programs and college initiatives throughout his tenure at Rollins

Methodological considerations in using AcciMaps and the Risk Management Framework to analyse large-scale systemic failures

In this paper we describe our use of the AcciMap and Risk Management (ActorMap) framework (RMF) to analyse two recent accidents – the infection outbreaks which occurred at the Maidstone and Tunbridge Wells NHS Trust and the 2005 Stockwell Shooting incident. Previous work using AcciMaps and the RMF is described and reviewed in section 2 of the paper. We then describe the case studies followed by an account of our goals and the procedure used to carry out the accident analyses (section 3). The differences in our use of the methods are described in section 4 of the paper. Finally, we reflect on these differences in order to develop of a set of criteria which could be used to scope more detailed guidelines for the selection and use of the two methods

Lessons learnt from using AcciMaps and the risk management framework to analyse large-scale systemic failures

In this paper we describe our experiences in using AcciMaps and the Risk Management (ActorMap) framework (RMF) to analyse two recent accidents – the infection outbreaks which occurred at the Maidstone and Tunbridge Wells NHS Trust and the 2005 Stockwell Shooting incident. We first review previous work using AcciMaps and the RMF, followed by an account of our goals and the procedure used to carry out the accident analyses and the differences in our use of the methods. Finally, we reflect on these differences in order to develop of a set of criteria which could be used to scope more detailed guidelines for the selection and use of the two methods

Ariel - Volume 8 Number 5

Executive Editor James W. Lockard. Jr. Business Manager Neeraj K. Kanwal University News Martin Trichtinger World News Doug Hiller Opinions Elizabeth A. McGuire Features Patrick P. Sokas Sports Desk Shahab S. Minassian Managing Editor Edward H. Jasper Managing Associate Brenda Peterson Photography Editor Robert D. Lehman, Jr. Graphics Christine M. Kuhnl

The Vascular Flora of Three Top Mountain Game Land Preserve, Ashe County, North Carolina

This study documented the flora of a Game Land Preserve on an isolated massif in Ashe County, North Carolina from Spring 2009 – Summer 2011. 317 taxa from 198 genera and 94 families compose the flora at Three Top Mountain Game Land Preserve. Of these 317 taxa, 27 taxa are listed as imperiled by the U.S. or North Carolina, including Liatris helleri, Geum radiatum, Houstonia montana, and Juncus trifidus. This flora is the only documentation of Campanula rotundifolia in the state of North Carolina. In addition to the previously documented communities, a Carolina Hemlock Forest community was documented. The flora compares with the other studies in the area, sharing similarities and showing variations in floristic composition. The flora compares with the expected number of taxa based on the generated species area curve from Southern Appalachian floras. This study addressed the challenges faced by botanists conducting floristic studies by introducing botanist and ecological effects that should be acknowledged when completing floristic studies and using floristic data. A cautionary note on the need to gather more data about floristic studies to be able to compare results appropriately is presented, as well as a theoretical model for the completion of a floristic study

Exploring the impact of gastrointestinal parasitic helminths on the human microbiome using advanced biomolecular and bioinformatics technologies

Our understanding of the biology of human gastrointestinal (GI) parasitic helminths is greater than ever before. However, so far, the research has focused on gene expression profiling, immune- and protein-protein interactions in host-parasite systems. The importance of parasite microbiota interactions has, so far, been largely overlooked. The microbiome is key to host health and it has been demonstrated that the balance between the gut microbiota and the host is crucial for health maintenance and that a disturbance of this balance can result in a range of diseases. Hence, given that GI nematodes and the gut microbiota share the same ecological niche within the human host, it is plausible that GI helminths and the host microbiota interact, and that this could significantly impact on the health and homeostasis of the parasite-infected hosts. Fortunately, the availability and affordability of next generation sequencing now enables us to investigate such host-parasite-microbiota interactions in depth and at high throughput. Therefore, the aims of this thesis were to explore the impact of such helminth infections in various systems, ranging from natural multi-species infections in a developing country to highly controlled and experimental infections involving a single species of parasitic helminth. This would allow the identification of microbiome changes that are consistent across different settings, as well as help detect alterations that are specific to a certain host-helminth system. Thus, the main aims of the thesis were: (i) to investigate the consequences of natural multi- or mono-species infections by helminth parasites on the composition of the human gut microbiota (Chapters 2 and 3), (ii) to elucidate the longitudinal impact of experimentally controlled monospecies helminth infections on the human gut microbiota (Chapter 4), (iii) and to examine whether an extra-intestinal (EI) helminth infection has an impact on the host microbiome in a murine model of human schistosomiasis (Chapter 5). Overall, I found that GI and EI helminths have a substantial impact on the host gut microbiota, both on individual taxa and on a community level. Many of the observed changes appeared to be specific to the host-helminth system that was being investigated, yet some consistencies emerged. Firstly, low level, long term, and single species infections that were not accompanied by pathology appeared to increase the gut microbial diversity within their host and promote a stable and healthy gut microbial composition (Chapters 3 and 4). Contrarily, acute heavy burden infections, associated with pathology, appeared to have the opposite effect, i.e. reducing the overall diversity of the host’s gut microbiome and promoting the proliferation of opportunistic pathogens (Chapters 2 and 5). This suggests that parasitic helminth infections could detrimentally impact the hosts they infect besides the direct pathology they induce, but also adds further weight to the idea of a therapeutic use of helminths in the context of helminth therapy. Indeed, the beneficial effect helminths can have on the host gut microbiota, together with the mounting evidence towards an intrinsic link between autoimmune diseases and the microbiome, might present a mechanism through which helminths could exert a therapeutic effect on patients suffering from such conditions. In, conclusion the present thesis has contributed significantly by providing entirely new insights into the impact of natural and experimental parasitic helminth infections on the human gut microbiome (Chapter 6). The findings provide a sound basis for future fundamental investigations of, for example, the relationship of helminth species, abundance, and host to microbiome changes in the context of infection. However, the results also act as a stepping stone for studies exploring the translational potential of helminth-microbiota interactions, such as the role that helminth induced microbiome modulations play in infection pathology, or whether such changes play a key role in the therapeutic potential of helminth therapy.BBSRC DT