Nominally volatile-free mantle minerals: a reservoir for water and fluorine in the Kaapvaal Craton

The extent to which Earth’s sub-cratonic lithospheric mantle acts as a major repository for volatile elements is poorly constrained. This study presents the first systematic investigation into water, fluorine and chlorine storage in nominally volatile-free mantle minerals from sub-cratonic mantle. Full petrologic and chemical characterisation (using EPMA, LA-ICP-MS, SIMS, FTIR, SEM, EBSD) of nineteen mantle xenoliths from the interior (Bultfontein, South Africa) and margin (Mothae, Lesotho) of the Kaapvaal craton has placed important constraints on the capacity of olivine and pyroxenes to store volatiles. Cryptically metasomatised olivine is found to be a major host of fluorine (up to 196 ppm). A new incorporation mechanism involving triple coupling of F, OH and Ti in olivine is recognised: Ti4+ in an octahedral site is charge balanced by F− in an oxygen site and OH− in a neighbouring tetrahedral vacancy. This triple coupling limits the independent diffusion of each element and hence preserves metasomatic enrichment on timescales of millions to billions of years. Four different types of metasomatism have been recognised in the Kaapvaal xenolith suites, each with different controls on the storage of volatile elements in olivine and pyroxenes. Proto-kimberlite metasomatism is found to flux the largest amount of volatile elements into the sub-cratonic lithospheric mantle. This has important implications for the pre-conditioning of the mantle prior to the host kimberlite eruption, because assimilation of volatile-rich mantle wall-rock contributes volatile species to kimberlite magmas and drives their ascent through hundreds of kilometres of lithosphere to the surface. The Kaapvaal craton has previously been considered as dry compared to the Slave and Siberian cratons but this new dataset includes water concentrations of clinopyroxene and orthopyroxene that are as high as those in the published literature. Olivine F concentrations are some of the highest recorded in global lithospheric mantle and provide evidence that F input at subduction zones is recycled through the convecting mantle, transported into the cratonic mantle by small-fraction melts and stored in both NVFMMs and new metasomatic phases. A metasomatic front at 120 km depth coincides with high concentrations of volatiles and corresponds to seismic mid-lithospheric discontinuities and has important implications for craton stability.NERC DTP Studentshi

A comparative analysis of the student movements in the United States and Japan, 1964-1970

The basic question seems to be this: are there, indeed, any experiences similar enough to say that the basic causes of student unrest in the United States and Japan are the same? I would hypothesize that there are. It is my thesis that student unrest and the causes of student unrest in highly advanced countries are similar. While students may be dissatisfied with the same structures within their societies. Therefore, I intend to demonstrate in this paper, my thesis that student unrest and the cause of student unrest in modern countries are similar

Estimates of the transmissibility of the 1968 (Hong Kong) influenza pandemic: evidence of increased transmissibility between successive waves.

The transmissibility of the strain of influenza virus which caused the 1968 influenza pandemic is poorly understood. Increases in outbreak size between the first and second waves suggest that it may even have increased between successive waves. The authors estimated basic and effective reproduction numbers for both waves of the 1968 influenza pandemic. Epidemic curves and overall attack rates for the 1968 pandemic, based on clinical and serologic data, were retrieved from published literature. The basic and effective reproduction numbers were estimated from 46 and 17 data sets for the first and second waves, respectively, based on the growth rate and/or final size of the epidemic. Estimates of the basic reproduction number (R(0)) were in the range of 1.06-2.06 for the first wave and, assuming cross-protection, 1.21-3.58 in the second. Within each wave, there was little geographic variation in transmissibility. In the 10 settings for which data were available for both waves, R(0) was estimated to be higher during the second wave than during the first. This might partly explain the larger outbreaks in the second wave as compared with the first. This potential for change in viral behavior may have consequences for future pandemic mitigation strategies

Internet research and the implications for ethical research practice

The Internet has extended the opportunity for researchers to investigate human actions and interactions. This study aims to critically examine the various ways that ethical considerations associated with Internet-Mediated Research (IMR) are constructed as a social reality by Australian Human Research Ethics Committee (HREC) and the implications for research practice. This project builds on research undertaken in the United States by Buchannan and Ess (2009) which discussed US Institutional Review Boards (IRBs) and the state of Internet research ethics. An explanatory sequential mixed design, consisting of two distinct phases was conducted (Creswell & Plano Clark, 2003). Quantitative data was collected and analysed in the first phase (Study 1) via an online survey of Australian Human Research Ethics Committee members from March to April 2016. Semi-structured interviews (n=3) were then conducted with Chairpersons of Australian Human Research Ethics Committees (Study 2) and analysed to further explain and clarify results found in the first data collection phase. Results of current processes and practices of Australian HRECs obtained in Study 1 were found to be similar to those reported by US IRBs and suggested that ethical review boards may be ill-equipped and ill-trained to navigate the review of IMR protocols. However, the addition of a qualitative overlay via the Australian HREC Chairperson’s interviews in Study 2 provided additional detail that suggested that reviewing IMR protocols is more complex than previously understood. Thematic analysis of the interview data identified that the ethical review of IMR protocols is thoroughly undertaken via a principle-based process as it is not viewed as being different to any other research method or tool. Additionally, ethical responsibility in this space is shared amongst the HREC, researchers, and participants themselves

The emergence of resistance to the benzimidazole anthlemintics in parasitic nematodes of livestock is characterised by multiple independent hard and soft selective sweeps

Anthelmintic resistance is a major problem for the control of parasitic nematodes of livestock and of growing concern for human parasite control. However, there is little understanding of how resistance arises and spreads or of the “genetic signature” of selection for this group of important pathogens. We have investigated these questions in the system for which anthelmintic resistance is most advanced; benzimidazole resistance in the sheep parasites Haemonchus contortus and Teladorsagia circumcincta. Population genetic analysis with neutral microsatellite markers reveals that T. circumcincta has higher genetic diversity but lower genetic differentiation between farms than H. contortus in the UK. We propose that this is due to epidemiological differences between the two parasites resulting in greater seasonal bottlenecking of H. contortus. There is a remarkably high level of resistance haplotype diversity in both parasites compared with drug resistance studies in other eukaryotic systems. Our analysis suggests a minimum of four independent origins of resistance mutations on just seven farms for H. contortus, and even more for T. circumincta. Both hard and soft selective sweeps have occurred with striking differences between individual farms. The sweeps are generally softer for T. circumcincta than H. contortus, consistent with its higher level of genetic diversity and consequent greater availability of new mutations. We propose a model in which multiple independent resistance mutations recurrently arise and spread by migration to explain the widespread occurrence of resistance in these parasites. Finally, in spite of the complex haplotypic diversity, we show that selection can be detected at the target locus using simple measures of genetic diversity and departures from neutrality. This work has important implications for the application of genome-wide approaches to identify new anthelmintic resistance loci and the likelihood of anthelmintic resistance emerging as selection pressure is increased in human soil-transmitted nematodes by community wide treatment programs

"She Was No Beauty, But-" The Careers and Public Images of Pauline Viardot, Emma Calvé, and Sibyl Sanderson

In the late nineteenth and early twentieth centuries, female singers were at the heart of the opera scene. Prima donnas experienced more power on and off the stage as artists and as celebrities in this period than perhaps any other. They were central in negotiations with distribution of arias in operas, visits to the impresario, theater owners and composers, dressing rooms, carriages to take them to their destinations, and more. They collaborated with the composers who wrote for them, performed title roles in a significant number of operas, and were widely loved by the public. These women’s identities, however, presented perhaps a unique dichotomy. They were both a seductive siren and a powerful and financially independent career woman. They held agency, yet they were also seen as an object for consumption and pleasure. Many of these divas left a legacy of distinct and well-designed careers, as well as the memory of voices that drew an entire public to them. While it may seem, at first glance, that their long-lasting careers were a result of their voices alone, looking deeper shows us that they crafted their brand carefully. In this thesis, I explore how three nineteenth-century singers shaped their public personas and brand in terms of their interactions with the press, their colleagues, and their audience through career moves and publicly-released images. I seek to illustrate that there were numerous factors beyond the diva’s voice that contributed to the trajectory of her career, many of which were shaped by a diva’s own agency. I have chosen, as my case studies, three singers whose careers centered around Paris in particular: Pauline Viardot, Sibyl Sanderson, and Emma Calvé. While each singer had a unique career that drew attention to different parts of their identities as women and singers, all three needed to cope with the misogyny inherent in nineteenth-century patriarchy. For that reason, each singer developed her own strategies around a system that was challenging both in professional and personal ways.Bachelor of Art

Lack of safe drinking water for lake Chapala basin communities in Mexico inhibits progress toward sustainable development goals 3 and 6.

Background: Access to safe, affordable and accessible drinking water is a human right and foundational to the third and sixth World Health Organization’s Sustainable Development Goals (SDGs). Unsafe drinking water is a risk factor for chronic and enteric diseases. Both chronic kidney disease (CKD) and diarrheal disease are highly prevalent in the Lake Chapala basin, Jalisco, Mexico, suggesting disparities in factors leading to successful achievement of these two SDGs. Methods: This study aimed to assess progress towards SDG three and six in the Lake Chapala basin. Qualitative, quantitative, and geospatial data were collected between May and August of 2019 from three towns within the municipalities of Poncitlán and Chapala. Results: Ninety-nine households participated in this study. Water sampling analyses determined 81.18% of samples from water jugs (garrafones) and 70.05% of samples from tap water were contaminated with total coliform bacteria, often including E. coli. Additionally, 32% of garrafón samples and 61.9% of tap water samples had detectable levels of arsenic. Approximately 97.94% of respondents stated that they believe clean water is a human right, but 78.57% feel the Mexican government does not do enough to make this a reality. Conclusions: This mixed methods approach highlights water quality as a serious issue in communities around Lake Chapala, and demonstrates inadequate drinking water as a key hazard, potentially perpetuating the high disease burden of both CKD and enteric disease in the region.ITESO, A.C

Be a Part of the Plan - Engaging People - Linking the World

Exploring efforts to increase broadband adoption and utilization in Nebraska will increase community vitality and economic growth. The Nebraska Broadband Initiative, which is in its third year, is designed to increase adoption and utilization of broadband in communities/regions with an empasis on unserved and underserved regions. Following are a few highlights on current activities

On Numerical Semigroups with Almost-Maximal Genus

A numerical semigroup is a cofinite subset of N0, containing 0, that is closed under addition.  Its genus is the number of nonnegative integers that are missing.  A numerical set is a similar object, not necessarily closed under addition.  If T is a numerical set, then A(T)={n in N0 : n+T is a subset of T} is a numerical semigroup.  Recently a paper appeared counting the number of numerical sets T where A(T) is a numerical semigroup of maximal genus.  We count the number of numerical sets T where A(T) is a numerical semigroup of almost-maximal genus, i.e. genus one smaller than maximal