scholarly journals Insights into the Geomicrobiology of Biovermiculations from Rock Billet Incubation Experiments

Life ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 59
Author(s):  
Hilary Kelly ◽  
Michael N. Spilde ◽  
Daniel S. Jones ◽  
Penelope J. Boston

Biovermiculations are uniquely patterned organic rich sediment formations found on the walls of caves and other subterranean environments. These distinctive worm-like features are the combined result of physical and biological processes. The diverse microbial communities that inhabit biovermiculations may corrode the host rock, form secondary minerals, and produce biofilms that stabilize the sediment matrix, thus altering cave surfaces and contributing to the formation of these wall deposits. In this study, we incubated basalt, limestone, and monzonite rock billets in biovermiculation mixed natural community enrichments for 468–604 days, and used scanning electron microscopy (SEM) to assess surface textures and biofilms that developed over the course of the experiment. We observed alteration of rock billet surfaces associated with biofilms and microbial filaments, particularly etch pits and other corrosion features in olivine and other silicates, calcite dissolution textures, and the formation of secondary minerals including phosphates, clays, and iron oxides. We identified twelve distinct biofilm morphotypes that varied based on rock type and the drying method used in sample preparation. These corrosion features and microbial structures inform potential biological mechanisms for the alteration of cave walls, and provide insight into possible small-scale macroscopically visible biosignatures that could augment the utility of biovermiculations and similarly patterned deposits for astrobiology and life detection applications.

2021 ◽  
pp. 1-17
Author(s):  
Emma Davidson ◽  
Briege Nugent ◽  
Sarah Johnsen

This article reflects on the contribution of qualitative longitudinal research (QLR) to understandings of homeless peoples’ experiences of support service interventions in an era of austerity in the UK. It brings into ‘analytic conversation’ data from qualitative longitudinal evaluations of homeless support projects operated by voluntary sector organisations in Scotland. With fieldwork spanning 2014-2019, the analysis expands the analytical potential of pooling small-scale studies through an interrogation of individuals’ ‘journeys’ through homelessness services and their rough path to ‘home’. By reflecting on our substantive findings, the article explores the added value and challenges of a longitudinal approach. It concludes that while QLR can deliver deep insight into lives lived by vulnerable populations and potentially reduce the distance between policy makers and those affected, its benefits must be balanced against pragmatism and the ethical responsibilities associated with the method.


2021 ◽  
Vol 12 (1) ◽  
pp. 37-76
Author(s):  
Sanja Škifić ◽  
Antonia Strika

This paper focuses on sociocultural and language-related issues among Croatian immigrants in Canada. It presents the results of thestudy conducted from November 2018 to February 2019 among Croatian immigrants of different generations in Ontario and British Columbia. Questions included in the questionnaire refer to different aspects of participants’ identity and their (families’) immigration, as well as issues related to their attitudes towards the homeland and engagement in Croatian associations in Canada. Participants were asked to provide feedback on their language acquisition, competence and use, as well as evaluations of the importance of the Croatian language for their identity. The questionnaire also contained questions related to participants’ language use from emotional and cognitive perspectives. Conclusions drawn on the basis of the collected data provide an insight into Croatian immigrants’ language use, the extent of cultural integration and language maintenance, and their attitudes towards the relationship between identity and language.


2000 ◽  
Author(s):  
Robin C. Redfield

Abstract Models of a small-scale water rocket are developed as an example of open system modeling by both the bond graph approach and a more classical method. One goal of the development is to determine the benefits of the bond graph approach into affording insight into the system dynamics. Both modeling approaches yield equivalent differential equations as they should, while the bond graph approach yields significantly more insight into the system dynamics. If a modeling goal is to simply find the system equations and predict behavior, the classical approach may be more expeditious. If insight and ease of model modification are desired, the bond graph technique is probably the better choice. But then you have to learn it!


Author(s):  
Christina Rudolph ◽  
Jürgen Grabe ◽  
Britta Bienen

Offshore monopiles are usually designed using the p-y method for cyclic loading. While the method works for static loading, it was not developed for high numbers of cycles. Since the turbines are highly sensitive towards tilting, cyclic loading must be considered. The static results should therefore be combined with results from cyclic model tests with a high number of cycles to account for the accumulation of displacement or rotation during the lifetime of these structures. These model tests can underestimate the accumulation, however, as it has recently been shown that a change of loading direction can increase the accumulation considerably. These results have been verified using small scale modeling and centrifuge testing. The results from modeling the full problem of a laterally loaded pile are compared here with results from cyclic simple shear tests with a change of shearing direction during the cyclic loading. For these tests, a newly developed apparatus is used. This allows further insight into the question how a soil can “retain a memory” of its loading history.


1976 ◽  
Vol 71 ◽  
pp. 323-344 ◽  
Author(s):  
K.-H. Rädler

One of the most striking features of both the magnetic field and the motions observed at the Sun is their highly irregular or random character which indicates the presence of rather complicated magnetohydrodynamic processes. Of great importance in this context is a comprehension of the behaviour of the large scale components of the magnetic field; large scales are understood here as length scales in the order of the solar radius and time scales of a few years. Since there is a strong relationship between these components and the solar 22-years cycle, an insight into the mechanism controlling these components also provides for an insight into the mechanism of the cycle. The large scale components of the magnetic field are determined not only by their interaction with the large scale components of motion. On the contrary, a very important part is played also by an interaction between the large and the small scale components of magnetic field and motion so that a very complicated situation has to be considered.


2007 ◽  
Vol 8 (3) ◽  
pp. 301-316 ◽  
Author(s):  
S.A. Bekessy ◽  
K. Samson ◽  
R.E. Clarkson

PurposeThis paper aims to assess the impact and value of non‐binding agreements or declarations in achieving sustainability in universities.Design/methodology/approachA case study of Royal Melbourne Institute of Technology (RMIT) University is presented, analysing the reasons for lack of progress towards sustainability and evaluating best ways forward. Using a timeline and analysis of historical records for the 12 years since RMIT first engaged in the sustainability agenda, major trends in the process of implementing policies are identified. Secondly, 15 semi‐structured interviews with university leaders and key sustainability stakeholders from across the university are analysed to provide insight into how and why the university has failed to achieve sustainability.FindingsNew implications for successfully achieving sustainability arise from these findings. Accountability is a key issue, as RMIT appears to reap benefits from being signatory to declarations without achieving genuine progress. To ensure that declarations are more than simply greenwash, universities must open themselves up to scrutiny of progress to determine whether commitments have been honoured.Practical implicationsRelying on small‐scale “club” activities establishing demonstrations and raising awareness is unlikely to lead to permanent change. The evidence of RMIT's engagement with sustainability shows that, for example, even when successful pilot studies are conducted, these initiatives may do little to affect the mainstream practices of a university unless certain conditions exist. Furthermore, given the on‐paper commitments institutions have made, and the role of the university in society, small‐scale and gradual changes in university practice are a far from adequate response to the urgent sustainability imperative.Originality/valueThe initial engagement of RMIT University with the sustainability agenda 12 years ago marked it as a world leader in sustainability best‐practice. Analysing how and why such a disappointing lack of action has resulted from such promising beginnings provides insight into future directions for implementing sustainability in universities. The paper argues that considering the key responsibility of universities in leading the sustainability agenda, a more systemic and serious response is required.


1999 ◽  
Vol 169 ◽  
pp. 255-259
Author(s):  
Regina E. Schulte-Ladbeck ◽  
Anna Pasquali ◽  
Mark Clampin ◽  
Antonella Nota ◽  
John Hillier ◽  
...  

AbstractWe have taken advantage of the high spatial resolution attainable with the HST to map the linear polarization in the V band across the nebulosity surrounding Eta Car. There are several new results related to polarization variations on different size scales. First, we present a two-dimensional map of the amount and position angle of the polarization across the Homunculus. Second, we provide measurements of the polarization within prominent features such as the “jet”, the “paddle”, the “skirt”, and the “spot” in the south-eastern lobe. Third, we comment on polarization variations associated with the small-scale structure that can be seen in HST images (and which gives the lobes their cauliflower-like appearance). The new data provide insight into the three-dimensional distribution of dust about Eta Car.


Pathogens ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 602
Author(s):  
Jennifer Geddes-McAlister

The pathogenesis of fungal and bacterial microbes is a complex process involving distinct parameters, including virulence factors, nutrient sensing and availability, microbial signals, as well as host status and defense responses. Defining pathogenesis improves our understanding of how an organism causes diseases and provides insight into novel prospects to combat infection. The effects of pathogenic microbes have significant impact on diverse sectors, including health, agriculture, and economics, underscoring their immense importance in society. Articles in this Special Issue address unique aspects of microbial pathogenesis by exploring interactions between host and pathogen during infection, defining inflammatory immune responses, profiling the importance of essential microbial structures associated with virulence, and outlining critical considerations driving complex diseases.


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