In-situ synchrotron characterization of fracture initiation and propagation in shales during indentation

The feasibility and advantages of synchrotron imaging have been demonstrated to effectively characterise fracture initiation and propagation in shales during indentation tests. These include 1) fast (minute-scale) and high-resolution (μm-scale) imaging of fracture initiation, 2) concurrent spatial and temporal information (4D) about fracture development, 3) quantification and modelling of shale deformation prior to fracture. Imaging experiments were performed on four shale samples with different laminations and compositions in different orientations, representative of three key variables in shale microstructure. Fracture initiation and propagation were successfully captured in 3D over time, and strain maps were generated using digital volume correlation (DVC). Subsequently, post-experimental fracture geometries were characterized at nano-scale using complementary SEM imaging. Characterisation results highlight the influence of microstructural and anisotropy variations on the mechanical properties of shales. The fractures tend to kink at the interface of two different textures at both macroscale and microscale due to deformation incompatibility. The average composition appears to provide the major control on hardness and fracture initiation load; while the material texture and the orientation of the indentation to bedding combine to control the fracture propagation direction and geometry. This improved understanding of fracture development in shales is potentially significant in the clean energy applications

Correlative multi-scale imaging of shales: A review and future perspectives

As the fastest growing energy sector globally, shale and shale reservoirs have attracted the attention of both industry and scholars. However, the strong heterogeneity at different scales and the extremely fine-grained nature of shales makes macroscopic and microscopic characterization highly challenging. Recent advances in imaging techniques have provided many novel characterization opportunities of shale components and microstructures at multiple scales. Correlative imaging, where multiple techniques are combined, is playing an increasingly important role in the imaging and quantification of shale microstructures (e.g. one can combine optical microscopy, scanning electron microscopy/transmission electron microscopy and X-ray radiography in 2D, or X-ray computed tomography and electron microscopy in 3D). Combined utilization of these techniques can characterize the heterogeneity of shale microstructures over a large range of scales, from macroscale to nanoscale (c. 100-10-9 m). Other chemical and physical measurements can be correlated to imaging techniques to provide complementary information for minerals, organic matter and pores. These imaging techniques and subsequent quantification methods are critically reviewed to provide an overview of the correlative imaging workflow. Applications of the above techniques for imaging particular features in different shales are demonstrated, and key limitations and benefits summarized. Current challenges and future perspectives in shale imaging techniques and their applications are discussed

Synchrotron tomographic quantification of strain and fracture during simulated thermal maturation of an organic-rich shale, UK Kimmeridge Clay

Analyzing the development of fracture networks in shale is important to understand both hydrocarbon migration pathways within and from source rocks and the effectiveness of hydraulic stimulation upon shale reservoirs. Here we use time‐resolved synchrotron X‐ray tomography to quantify in four dimensions (3‐D plus time) the development of fractures during the accelerated maturation of an organic‐rich mudstone (the UK Kimmeridge Clay), with the aim of determining the nature and timing of crack initiation. Electron microscopy (EM, both scanning backscattered and energy dispersive) was used to correlatively characterize the microstructure of the sample preheating and postheating. The tomographic data were analyzed by using digital volume correlation (DVC) to measure the three‐dimensional displacements between subsequent time/heating steps allowing the strain fields surrounding each crack to be calculated, enabling crack opening modes to be determined. Quantification of the strain eigenvectors just before crack propagation suggests that the main mode driving crack initiation is the opening displacement perpendicular to the bedding, mode I. Further, detailed investigation of the DVC measured strain evolution revealed the complex interaction of the laminar clay matrix and the maximum principal strain on incipient crack nucleation. Full field DVC also allowed accurate calculation of the coefficients of thermal expansion (8 × 10−5/°C perpendicular and 6.2 × 10−5/°C parallel to the bedding plane). These results demonstrate how correlative imaging (using synchrotron tomography, DVC, and EM) can be used to elucidate the influence of shale microstructure on its anisotropic mechanical behavior

Seroprevalence of HCV, HBV and HIV in two inner-city London Emergency Departments.

Summary: In this paper we build on work investigating the feasibility of human immunodeficiency virus (HIV) testing in emergency departments (EDs), estimating the prevalence of hepatitis B, C and HIV infections among persons attending two inner-London EDs, identifying factors associated with testing positive in an ED. We also undertook molecular characterisation to look at the diversity of the viruses circulating in these individuals, and the presence of clinically significant mutations which impact on treatment and control. Blood-borne virus (BBV) testing in non-traditional settings is feasible, with emergency departments (ED) potentially effective at reaching vulnerable and underserved populations. We investigated the feasibility of BBV testing within two inner-London EDs. Residual samples from biochemistry for adults (⩾18 years) attending The Royal Free London Hospital (RFLH) or the University College London Hospital (UCLH) ED between January and June 2015 were tested for human immunodeficiency virus (HIV)Ag/Ab, anti-hepatitis C (HCV) and HBsAg. PCR and sequence analysis were conducted on reactive samples. Sero-prevalence among persons attending RFH and UCLH with residual samples (1287 and 1546), respectively, were 1.1% and 1.0% for HBsAg, 1.6% and 2.3% for anti-HCV, 0.9% and 1.6% for HCV RNA, and 1.3% and 2.2% for HIV. For RFH, HBsAg positivity was more likely among persons of black vs. white ethnicity (odds ratio 9.08; 95% confidence interval 2.72–30), with anti-HCV positivity less likely among females (0.15, 95% CI 0.04–0.50). For UCLH, HBsAg positivity was more likely among non-white ethnicity (13.34, 95% CI 2.20–80.86 (Asian); 8.03, 95% CI 1.12–57.61 (black); and 8.11, 95% CI 1.13–58.18 (other/mixed)). Anti-HCV positivity was more likely among 36–55 year olds vs. ⩾56 years (7.69, 95% CI 2.24–26.41), and less likely among females (0.24, 95% CI 0.09–0.65). Persons positive for HIV-markers were more likely to be of black vs. white ethnicity (4.51, 95% CI 1.63–12.45), and less likely to have one ED attendance (0.39, 95% CI 0.17–0.88), or female (0.12, 95% CI 0.04–0.42). These results indicate that BBV-testing in EDs is feasible, providing a basis for further studies to explore provider and patient acceptability, referral into care and cost-effectiveness

“you just look at rocks, and have beards” Perceptions of Geology From the United Kingdom: A Qualitative Analysis From an Online Survey

In the last few decades, Geology courses, particularly in the Global North, have seen a decline in student enrolment. Geologists have linked this downturn to a lack of exposure to the subject at school and college level. This work seeks to understand the public’s relationship with Geology and draws on over 5,000 open-ended question responses to a survey disseminated in 2021. The survey asked both those who had, and had not, studied geology as a subject a series of questions in order to explore their perceptions of the discipline. Our findings indicate that individuals “outside” of geology see the subject as old fashioned, boring, and environmentally damaging; simply the study of rock samples with nothing new to be discovered from; and with poor job prospects outside of the oil and gas industry. Geologists who responded to the survey paint a picture of a broad, interdisciplinary subject, with vibrant employability opportunities—yet struggle to coherently and collectively describe this when asked, “what is geology?”. In addition to the identified perception of geology as boring, and notions of poor employability being a barrier to prospective students, diversity and inclusivity issues are highlighted as significant barriers by those who study geology. Our findings indicate that both geologists and the geology curriculum need to coherently describe what geology is more effectively. We need to develop and better communicate the subject’s interdisciplinary nature and links to critical societal issues, such as the role of responsible mineral extraction in the energy transition and the importance of geology in vital areas such as climate change science, water resource management, environmental conservation, and sustainable urban/built development. Finding new ways to show that, far from being boring, geology is a subject that can fundamentally change the way you see and interact with the world around you is of central importance to achieving this. Efforts to make the subject more equitable are also highlighted as being critical in creating a more inclusive and accessible discipline

Identifying key components for a psychological intervention for people with vitiligo - a quantitative and qualitative study in the United Kingdom using web-based questionnaires of people with vitiligo and healthcare professionals

UK Dermatology Clinical Trials Network Themed Research Call

Recommendations for combatting the diversity crisis in Geography, Earth and Environmental Science research; perspectives from the UK [abstract only]

The roots of modern geoscience lie in early colonial principles that land could belong to those willing to use its products, regardless of indigenous territories and practices. The production of geoscience knowledge has therefore been historically tied to a desire to explain the distribution and extractability of resources, largely for the benefit of the colonising force. This knowledge now has an essential role to play in equitable and sustainable development, but it cannot be successfully applied without diverse representation amongst geoscientists. However, Geoscience in the Global North is disproportionately white. Following on from the work of Bernard and Cooperdock in the USA, we highlight dismal representation data from Geography, Earth and Environmental Science (GEES) disciplines in UK HE and make recommendations for positive action based on evidenced effective practice. Geography, Earth and Environmental Sciences are the three worst Physical Science subjects for Black, Asian and Minority Ethnic student undergraduate participation in UK HE, and are very poor for retention of these students into postgraduate research (PGR). Physical Geography had just 5.2% PGR students who identified as Black, Asian, Mixed or Other (HESA data categories) in 2018/19. On average, over the past 5 years just 1.4% of postgraduate Geology PGR students were Black (HESA, 2020). By comparison, in the 2011 Census, 18.5% of UK 18-24 year olds were from Black, Asian or Minority Ethnic backgrounds, and 3.8% were Black. In two years out of the last five, no Black women have started PGR study in Geology or Physical Geography. Retention of Black, Asian and Minority Ethnic Physical Geography and Environmental Science students into PGR was worse in 2018/2019 than over the five years from 2014 to 2019; the situation is not improving with time (HESA, 2020) We summarise well-documented factors involved in inequity in research training across UK HE, and review subject-specific structural and cultural barriers to ethnic diversityin GEES subjects. These include early pipeline issues around access to nature, a scarcity of diverse role models, careers perceptions, and a lack of acknowledgement that the geosciences are deeply rooted in colonialism and white power. Our recommendations are wide-reaching, and build upon effective practice elsewhere. We take a whole-pipeline approach, making proposals that include both advocacy to remove barriers to entry (for example by combatting structural bias in application processes and accreditation requirements), and action to broaden participation (for example, by creating paid ambassador and internship schemes, and through decolonisation and inclusive pedagogic redesign). We must acknowledge the hostile environments that deter ethnic minority students from applying to, and continuing with, our discipline. We must address bias and be actively anti-racist. We must act now, to create a modern geoscience research culture that reflects the diverse nature of the planet we study

RNAseq Analyses Identify Tumor Necrosis Factor-Mediated Inflammation as a Major Abnormality in ALS Spinal Cord

ALS is a rapidly progressive, devastating neurodegenerative illness of adults that produces disabling weakness and spasticity arising from death of lower and upper motor neurons. No meaningful therapies exist to slow ALS progression, and molecular insights into pathogenesis and progression are sorely needed. In that context, we used high-depth, next generation RNA sequencing (RNAseq, Illumina) to define gene network abnormalities in RNA samples depleted of rRNA and isolated from cervical spinal cord sections of 7 ALS and 8 CTL samples. We aligned \u3e50 million 2X150 bp paired-end sequences/sample to the hg19 human genome and applied three different algorithms (Cuffdiff2, DEseq2, EdgeR) for identification of differentially expressed genes (DEG’s). Ingenuity Pathways Analysis (IPA) and Weighted Gene Co-expression Network Analysis (WGCNA) identified inflammatory processes as significantly elevated in our ALS samples, with tumor necrosis factor (TNF) found to be a major pathway regulator (IPA) and TNFα-induced protein 2 (TNFAIP2) as a major network “hub” gene (WGCNA). Using the oPOSSUM algorithm, we analyzed transcription factors (TF) controlling expression of the nine DEG/hub genes in the ALS samples and identified TF’s involved in inflammation (NFkB, REL, NFkB1) and macrophage function (NR1H2::RXRA heterodimer). Transient expression in human iPSC-derived motor neurons of TNFAIP2 (also a DEG identified by all three algorithms) reduced cell viability and induced caspase 3/7 activation. Using high-density RNAseq, multiple algorithms for DEG identification, and an unsupervised gene co-expression network approach, we identified significant elevation of inflammatory processes in ALS spinal cord with TNF as a major regulatory molecule. Overexpression of the DEG TNFAIP2 in human motor neurons, the population most vulnerable to die in ALS, increased cell death and caspase 3/7 activation. We propose that therapies targeted to reduce inflammatory TNFα signaling may be helpful in ALS patients