792 research outputs found

    Characterization of Biochars Produced From Peanut Hulls and Pine Wood with Different Pyrolysis Conditions

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    Background Application of modern biomass pyrolysis methods for production of biofuels and biochar is potentially a significant approach to enable global carbon capture and sequestration. To realize this potential, it is essential to develop methods that produce biochar with the characteristics needed for effective soil amendment. Methods Biochar materials were produced from peanut hulls and pine wood with different pyrolysis conditions, then characterized by cation exchange (CEC) capacity assays, nitrogen adsorptionā€“desorption isotherm measurements, micro/nanostructural imaging, infrared spectra and elemental analyses. Results Under a standard assay condition of pH 8.5, the CEC values of the peanut hull-derived biochar materials, ranging from 6.22 to 66.56 cmol kgāˆ’1, are significantly higher than those of the southern yellow pine-derived biochar, which are near zero or negative. The biochar produced from peanut hulls with a steam activation process yielded the highest CEC value of 66.56 cmol kgāˆ’1, which is about 5 times higher than the cation exchange capacity (12.51 cmol kgāˆ’1) of a reference soil sample. Notably, biochar produced from peanut hulls with batch barrel retort pyrolysis also has a much higher CEC value (60.12 cmol kgāˆ’1) than that (12.45 cmol kgāˆ’1) from Epridaā€™s H2-producing continuous steam injection process. The CEC values were shown to correlate well with the ratios of oxygen atoms to carbon atoms (O:C ratios) in the biochar materials. The higher O:C ratio in a biochar material may indicate the presence of more hydroxyl, carboxylate, and carbonyl groups that contribute to a higher CEC value for the biochar product. In addition, the increase in surface area can also play a role in increasing the CEC value of biochar, as in the case of the steam activation char. Conclusion Comparison of characterization results indicated that CEC value is determined not only by the type of the source biomass materials but also by the pyrolysis conditions. Biochar with the desirable characteristics of extremely high surface area (700 m2/g) and cation exchange capacity (\u3e 60 cmol kg) was created through steam activation

    Genome-wide screening for DNA variants associated with reading and language traits

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    This research was funded by: Max Planck Society, the University of St Andrews - Grant Number: 018696, US National Institutes of Health - Grant Number: P50 HD027802, Wellcome Trust - Grant Number: 090532/Z/09/Z, and Medical Research Council Hub Grant Grant Number: G0900747 91070Reading and language abilities are heritable traits that are likely to share some genetic influences with each other. To identify pleiotropic genetic variants affecting these traits, we first performed a genomeā€wide association scan (GWAS) metaā€analysis using three richly characterized datasets comprising individuals with histories of reading or language problems, and their siblings. GWAS was performed in a total of 1862 participants using the first principal component computed from several quantitative measures of readingā€ and languageā€related abilities, both before and after adjustment for performance IQ. We identified novel suggestive associations at the SNPs rs59197085 and rs5995177 (uncorrected Pā€‰ā‰ˆā€‰10ā€“7 for each SNP), located respectively at the CCDC136/FLNC and RBFOX2 genes. Each of these SNPs then showed evidence for effects across multiple reading and language traits in univariate association testing against the individual traits. FLNC encodes a structural protein involved in cytoskeleton remodelling, while RBFOX2 is an important regulator of alternative splicing in neurons. The CCDC136/FLNC locus showed association with a comparable reading/language measure in an independent sample of 6434 participants from the general population, although involving distinct alleles of the associated SNP. Our datasets will form an important part of onā€going international efforts to identify genes contributing to reading and language skills.Publisher PDFPeer reviewe

    Preassembled GPCR signaling complexes mediate distinct cellular responses to ultralow ligand concentrations

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    G proteinā€“coupled receptors (GPCRs) are the largest class of cell surface signaling proteins, participate in nearly all physiological processes, and are the targets of 30% of marketed drugs. Typically, nanomolar to micromolar concentrations of ligand are used to activate GPCRs in experimental systems. We detected GPCR responses to a wide range of ligand concentrations, from attomolar to millimolar, by measuring GPCR-stimulated production of cyclic adenosine monophosphate (cAMP) with high spatial and temporal resolution. Mathematical modeling showed that femtomolar concentrations of ligand activated, on average, 40% of the cells in a population provided that a cell was activated by one to two binding events. Furthermore, activation of the endogenous Ī²2-adrenergic receptor (Ī²2AR) and muscarinic acetylcholine M3 receptor (M3R) by femtomolar concentrations of ligand in cell lines and human cardiac fibroblasts caused sustained increases in nuclear translocation of extracellular signalā€“regulated kinase (ERK) and cytosolic protein kinase C (PKC) activity, respectively. These responses were spatially and temporally distinct from those that occurred in response to higher concentrations of ligand and resulted in a distinct cellular proteomic profile. This highly sensitive signaling depended on the GPCRs forming preassembled, higher-order signaling complexes at the plasma membrane. Recognizing that GPCRs respond to ultralow concentrations of neurotransmitters and hormones challenges established paradigms of drug action and provides a previously unappreciated aspect of GPCR activation that is quite distinct from that typically observed with higher ligand concentrations

    Prevalence of frailty and cognitive impairment in older transplant candidates - a preview to the Kidney Transplantation in Older People (KTOP): impact of frailty on outcomes study

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    Ā© The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Abstract: Background: Kidney transplantation in older people has increased, however older transplant recipients experience mixed outcomes that invariably impacts on their quality of life. The increased vulnerability of older end stage kidney disease patients to frailty and cognitive impairment, may partially explain the differences in outcomes observed. The Kidney Transplantation in Older People (KTOP): impact of frailty on clinical outcomes study is an active clinical study aiming to explore the experience of older people waiting for and undergoing transplantation. In this manuscript we present the study protocol, the study cohort, and the prevalence of frailty and cognitive impairment identified at recruitment. Methods: The KTOP study is a single centre, prospective, mixed methods, observational study. Recruitment began in October 2019. All patients aged 60 or above either active on the deceased donor waitlist or undergoing live donor transplantation were eligible for recruitment. Recruited participants completed a series of questionnaires assessing frailty, cognition, and quality of life, which are repeated at defined time points whilst on the waitlist and post-transplant. Clinical data was concurrently collected. Any participants identified as frail or vulnerable were also eligible for enrolment into the qualitative sub-study. Results: Two hundred eight participants have been recruited (age 60ā€“78). Baseline Montreal Cognitive Assessments were available for 173 participants, with 63 (36.4%) participants identified as having scores below normal (score < 26). Edmonton Frail Scale assessments were available for 184 participants, with 29 participants (15.8%) identified as frail (score ā‰„ 8), and a further 37 participants (20.1%) identified as being vulnerable (score 6ā€“7). Conclusion: In the KTOP study cohort we have identified a prevalence of 36.4% of participants with MoCA scores suggestive of cognitive impairment, and a prevalence of frailty of 15.8% at recruitment. A further 20.1% were vulnerable. As formal testing for cognition and frailty is not routinely incorporated into the work up of older people across many units, the presence and significance of these conditions is likely not known. Ultimately the KTOP study will report on how these parameters evolve over time and following a transplant, and describe their impact on quality of life and clinical outcomes.Peer reviewe

    The long non-coding RNA PCAT-1 promotes prostate cancer cell proliferation through cMyc.

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    Long non-coding RNAs (lncRNAs) represent an emerging layer of cancer biology, contributing to tumor proliferation, invasion, and metastasis. Here, we describe a role for the oncogenic lncRNA PCAT-1 in prostate cancer proliferation through cMyc. We find that PCAT-1-mediated proliferation is dependent on cMyc protein stabilization, and using expression profiling, we observed that cMyc is required for a subset of PCAT-1-induced expression changes. The PCAT-1-cMyc relationship is mediated through the post-transcriptional activity of the MYC 3\u27 untranslated region, and we characterize a role for PCAT-1 in the disruption of MYC-targeting microRNAs. To further elucidate a role for post-transcriptional regulation, we demonstrate that targeting PCAT-1 with miR-3667-3p, which does not target MYC, is able to reverse the stabilization of cMyc by PCAT-1. This work establishes a basis for the oncogenic role of PCAT-1 in cancer cell proliferation and is the first study to implicate lncRNAs in the regulation of cMyc in prostate cancer

    Effects of sample handling and storage on quantitative lipid analysis in human serum

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    There is sparse information about specific storage and handling protocols that minimize analytical error and variability in samples evaluated by targeted metabolomics. Variance components that affect quantitative lipid analysis in a set of human serum samples were determined. The effects of freeze-thaw, extraction state, storage temperature, and freeze-thaw prior to density-based lipoprotein fractionation were quantified. The quantification of high abundance metabolites, representing the biologically relevant lipid species in humans, was highly repeatable (with coefficients of variation as low as 0.01 and 0.02) and largely unaffected by 1ā€“3 freeze-thaw cycles (with 0ā€“8% of metabolites affected in each lipid class). Extraction state had effects on total lipid class amounts, including decreased diacylglycerol and increased phosphatidylethanolamine in thawed compared with frozen samples. The effects of storage temperature over 1Ā week were minimal, with 0ā€“4% of metabolites affected by storage at 4Ā°C, āˆ’20Ā°C, or āˆ’80Ā°C in most lipid classes, and 19% of metabolites in diacylglycerol affected by storage at āˆ’20Ā°C. Freezing prior to lipoprotein fractionation by density ultracentrifugation decreased HDL free cholesterol by 37% and VLDL free fatty acid by 36%, and increased LDL cholesterol ester by 35% compared with fresh samples. These findings suggest that density-based fractionation should preferably be undertaken in fresh serum samples because up to 37% variability in HDL and LDL cholesterol could result from a single freeze-thaw cycle. Conversely, quantitative lipid analysis within unfractionated serum is minimally affected even with repeated freeze-thaw cycles

    Tuberculosis susceptibility and vaccine protection are independently controlled by host genotype

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    The outcome of Mycobacterium tuberculosis infection and the immunological response to the bacillus Calmette-Guerin (BCG) vaccine are highly variable in humans. Deciphering the relative importance of host genetics, environment, and vaccine preparation for the efficacy of BCG has proven difficult in natural populations. We developed a model system that captures the breadth of immunological responses observed in outbred individual mice, which can be used to understand the contribution of host genetics to vaccine efficacy. This system employs a panel of highly diverse inbred mouse strains, consisting of the founders and recombinant progeny of the "Collaborative Cross" project. Unlike natural populations, the structure of this panel allows the serial evaluation of genetically identical individuals and the quantification of genotype-specific effects of interventions such as vaccination. When analyzed in the aggregate, our panel resembled natural populations in several important respects: the animals displayed a broad range of susceptibility to M. tuberculosis, differed in their immunological responses to infection, and were not durably protected by BCG vaccination. However, when analyzed at the genotype level, we found that these phenotypic differences were heritable. M. tuberculosis susceptibility varied between lines, from extreme sensitivity to progressive M. tuberculosis clearance. Similarly, only a minority of the genotypes was protected by vaccination. The efficacy of BCG was genetically separable from susceptibility to M. tuberculosis, and the lack of efficacy in the aggregate analysis was driven by nonresponsive lines that mounted a qualitatively distinct response to infection. These observations support an important role for host genetic diversity in determining BCG efficacy and provide a new resource to rationally develop more broadly efficacious vaccines. IMPORTANCE Tuberculosis (TB) remains an urgent global health crisis, and the efficacy of the currently used TB vaccine, M. bovis BCG, is highly variable. The design of more broadly efficacious vaccines depends on understanding the factors that limit the protection imparted by BCG. While these complex factors are difficult to disentangle in natural populations, we used a model population of mice to understand the role of host genetic composition in BCG efficacy. We found that the ability of BCG to protect mice with different genotypes was remarkably variable. The efficacy of BCG did not depend on the intrinsic susceptibility of the animal but, instead, correlated with qualitative differences in the immune responses to the pathogen. These studies suggest that host genetic polymorphism is a critical determinant of vaccine efficacy and provide a model system to develop interventions that will be useful in genetically diverse populations.This work, including the efforts of Hardy Kornfeld, was funded by HHS | National Institutes of Health (NIH) (HL081149). This work, including the efforts of Sam Behar, was funded by HHS | National Institutes of Health (NIH) (AI123286-01). This work, including the efforts of Clare Margaret Smith and Christopher Sassetti, was funded by Howard Hughes Medical Institute (HHMI)

    Quantum interference of electromechanically stabilized emitters in nanophotonic devices

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    Photon-mediated coupling between distant matter qubits may enable secure communication over long distances, the implementation of distributed quantum computing schemes, and the exploration of new regimes of many-body quantum dynamics. Nanophotonic devices coupled to solid-state quantum emitters represent a promising approach towards realization of these goals, as they combine strong light-matter interaction and high photon collection efficiencies. However, the scalability of these approaches is limited by the frequency mismatch between solid-state emitters and the instability of their optical transitions. Here we present a nano-electromechanical platform for stabilization and tuning of optical transitions of silicon-vacancy (SiV) color centers in diamond nanophotonic devices by dynamically controlling their strain environments. This strain-based tuning scheme has sufficient range and bandwidth to alleviate the spectral mismatch between individual SiV centers. Using strain, we ensure overlap between color center optical transitions and observe an entangled superradiant state by measuring correlations of photons collected from the diamond waveguide. This platform for tuning spectrally stable color centers in nanophotonic waveguides and resonators constitutes an important step towards a scalable quantum network

    Conceptualising social justice and sociocultural issues within physical education teacher education: international perspectives

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    Background: Physical education (PE) and physical education teacher education (PETE) have a substantialĀ literature base that advocates for students to develop a critical consciousness, appreciate multiple perspectives, and engage in actions to enhance social justice (Tinning 2016).Ā Analysing sociocultural issues, critically reflecting on beliefs, knowledge, biography and values, and developing a sense of agency to enact change, have been recognised as an integral part of the PETE knowledge base for some time (FernĆ”ndez-Balboa 1997).Ā However, there remain differences in how social justice itself is conceptualised and enacted. Social justice is aligned heavily with critical and ā€˜postā€™ theories where taking action for justice, democracy and power are central; but social justice is also found in humanist beliefs in student-centredness and equality and has been co-opted by neoliberal forces that promote individual responsibility. While a lack of consensus is not in itself a problem (Bialystok 2014), diverse definitions might contribute to confusion (Randall and Robinson 2016) and lead to uncertainty over what and how to teach for social justice. Purpose: In order to work towards greater certainty around concepts of social justice in the PETE community, this project sought to map variations in definition and conceptualisation of social justice and sociocultural issues among physical education teacher educators (PETEs) and physical education and sport pedagogy (PESP) educators, as part of a wider project on social justice and sociocultural perspectives and practices in PETE. Methods: PETE and PESP faculty (n=72) in North America, Europe, and Australasia engaged in an in-depth interview, during which they were asked how they define social justice and sociocultural issues. Additional information about participantsā€™ social identity was collected. A constant comparative method of analysing participantsā€™ definitions mapped a range of concepts building on the theoretical framework of neoliberal, humanist, critical and ā€˜postā€™ approaches to social justice. Findings: The data demonstrate that there are a range of understandings about sociocultural issues and social justice. Most commonly, some participants articulated a humanist approach to social justice by encouraging their pre-service teachers (PSTs) to have awareness of equality of opportunity in relation to gender, sexuality and/or racism. Less prevalent, but strongly stated by those who conceptualised social justice in these terms, was the importance to take action for democracy, empowerment or critical reflection. The terms diversity and equality, framed in neoliberal and humanist discourses, were most commonly used within the United States (US), while critical pedagogy and alignment with critical and ā€˜postā€™ theories were more prevalent in Australia and New Zealand. Conclusion: Differences exist in the ways social justice is conceptualised in PETE. While this can be attributed to the influence of local issues, it is also reflective of what intellectual tools, such as humanism or critical theory, are available for problematising social issues. The range of non-critical concepts found raises concern that PSTs are not getting the tools to enact social justice or tackle sociocultural issues.

    The corona of a surface bubble promotes electrochemical reactions

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    The evolution of gaseous products is a feature common to several electrochemical processes, often resulting in bubbles adhering to the electrodeā€™s surface. Adherent bubbles reduce the electrode active area, and are therefore generally treated as electrochemically inert entities. Here, we show that this general assumption does not hold for gas bubbles masking anodes operating in water. By means of imaging electrochemiluminescent systems, and by studying the anisotropy of polymer growth around bubbles, we demonstrate that gas cavities adhering to an electrode surface initiate the oxidation of water-soluble species more effectively than electrode areas free of bubbles. The corona of a bubble accumulates hydroxide anions, unbalanced by cations, a phenomenon which causes the oxidation of hydroxide ions to hydroxyl radicals to occur at potentials at least 0.7 V below redox tabled values. The downhill shift of the hydroxide oxidation at the corona of the bubble is likely to be a general mechanism involved in the initiation of heterogeneous electrochemical reactions in water, and could be harnessed in chemical synthesis.S.C., N.D., and M.L.C. were supported by the Australian Research Council (grant nos. DP190100735, FT190100148, FL170100041, and CE140100012). M.L.C. acknowledges generous supercomputing time from the National Computational Infrastructure. C.W.E. and K.S.I. acknowledge the facilities and technical assistance of Microscopy Australia at the Centre for Microscopy, Characterisation & Analysis, The University of Western Australia, a facility funded by the University, State and Commonwealth Government
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