245 research outputs found

    Engineering of a wheat germ expression system to provide compatibility with a high throughput pET-based cloning platform

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    Wheat germ cell-free methods provide an important approach for the production of eukaryotic proteins. We have developed a protein expression vector for the TNT® SP6 High-Yield Wheat Germ Cell-Free (TNT WGCF) expression system (Promega) that is also compatible with our T7-based Escherichia coli intracellular expression vector pET15_NESG. This allows cloning of the same PCR product into either one of several pET_NESG vectors and this modified WGCF vector (pWGHisAmp) by In-Fusion LIC cloning (Zhu et al. in Biotechniques 43:354–359, 2007). Integration of these two vector systems allowed us to explore the efficacy of the TNT WGCF system by comparing the expression and solubility characteristics of 59 human protein constructs in both WGCF and pET15_NESG E. coli intracellular expression. While only 30% of these human proteins could be produced in soluble form using the pET15_NESG based system, some 70% could be produced in soluble form using the TNT WGCF system. This high success rate underscores the importance of eukaryotic expression host systems like the TNT WGCF system for eukaryotic protein production in a structural genomics sample production pipeline. To further demonstrate the value of this WGCF system in producing protein suitable for structural studies, we scaled up, purified, and analyzed by 2D NMR two 15N-, 13C-enriched human proteins. The results of this study indicate that the TNT WGCF system is a successful salvage pathway for producing samples of difficult-to-express small human proteins for NMR studies, providing an important complementary pathway for eukaryotic sample production in the NESG NMR structure production pipeline

    Accidental stability of dark matter

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    We propose that dark matter is stable as a consequence of an accidental Z2 that results from a flavour-symmetry group which is the double-cover group of the symmetry group of one of the regular geometric solids. Although model-dependent, the phenomenology resembles that of a generic Higgs portal dark matter scheme.Comment: 12 pages, final version, published in JHE

    Bianchi Type-II String Cosmological Models in Normal Gauge for Lyra's Manifold with Constant Deceleration Parameter

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    The present study deals with a spatially homogeneous and anisotropic Bianchi-II cosmological models representing massive strings in normal gauge for Lyra's manifold by applying the variation law for generalized Hubble's parameter that yields a constant value of deceleration parameter. The variation law for Hubble's parameter generates two types of solutions for the average scale factor, one is of power-law type and other is of the exponential form. Using these two forms, Einstein's modified field equations are solved separately that correspond to expanding singular and non-singular models of the universe respectively. The energy-momentum tensor for such string as formulated by Letelier (1983) is used to construct massive string cosmological models for which we assume that the expansion (θ\theta) in the model is proportional to the component σ 11\sigma^{1}_{~1} of the shear tensor σij\sigma^{j}_{i}. This condition leads to A=(BC)mA = (BC)^{m}, where A, B and C are the metric coefficients and m is proportionality constant. Our models are in accelerating phase which is consistent to the recent observations. It has been found that the displacement vector β\beta behaves like cosmological term Λ\Lambda in the normal gauge treatment and the solutions are consistent with recent observations of SNe Ia. It has been found that massive strings dominate in the decelerating universe whereas strings dominate in the accelerating universe. Some physical and geometric behaviour of these models are also discussed.Comment: 24 pages, 10 figure

    A microscale protein NMR sample screening pipeline

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    As part of efforts to develop improved methods for NMR protein sample preparation and structure determination, the Northeast Structural Genomics Consortium (NESG) has implemented an NMR screening pipeline for protein target selection, construct optimization, and buffer optimization, incorporating efficient microscale NMR screening of proteins using a micro-cryoprobe. The process is feasible because the newest generation probe requires only small amounts of protein, typically 30–200 μg in 8–35 μl volume. Extensive automation has been made possible by the combination of database tools, mechanization of key process steps, and the use of a micro-cryoprobe that gives excellent data while requiring little optimization and manual setup. In this perspective, we describe the overall process used by the NESG for screening NMR samples as part of a sample optimization process, assessing optimal construct design and solution conditions, as well as for determining protein rotational correlation times in order to assess protein oligomerization states. Database infrastructure has been developed to allow for flexible implementation of new screening protocols and harvesting of the resulting output. The NESG micro NMR screening pipeline has also been used for detergent screening of membrane proteins. Descriptions of the individual steps in the NESG NMR sample design, production, and screening pipeline are presented in the format of a standard operating procedure

    Actions in Practice: On details in collections

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    Several of the contributions to the Lynch et al. Special issue make the claim that conversation- analytic research into epistemics is ‘routinely crafted at the expense of actual, produced and constitutive detail, and what that detail may show us’. Here, we seek to address the inappositeness of this critique by tracing precisely how it is that recognizable actions emerge from distinct practices of interaction. We begin by reviewing some of the foundational tenets of conversation-analytic theory and method – including the relationship between position and composition, and the making of collections – as these appear to be primary sources of confusion for many of the contributors to the Lynch et al. Special Issue. We then target some of the specific arguments presented in the Special Issue, including the alleged ‘over-hearer’s’ writing of metrics, the provision of so- called ‘alternative’ analyses and the supposed ‘crafting’ of generalizations in epistemics research. In addition, in light of Lynch’s more general assertion that conversation analysis (CA) has recently been experiencing a ‘rapprochement’ with what he disparagingly refers to as the ‘juggernaut’ of linguistics, we discuss the specific expertise that linguists have to offer in analyzing particular sorts of interactional detail. The article as a whole thus illustrates that, rather than being produced ‘at the expense of actual, produced and constitutive detail’, conversation-analytic findings – including its work in epistemics – are unambiguously anchored in such detail. We conclude by offering our comments as to the link between CA and linguistics more generally, arguing that this relationship has long proven to be – and indeed continues to be – a mutually beneficial one

    The 12 Item Social and Economic Conservatism Scale (SECS)

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    Recent years have seen a surge in psychological research on the relationship between political ideology (particularly conservatism) and cognition, affect, behaviour, and even biology. Despite this flurry of investigation, however, there is as yet no accepted, validated, and widely used multi-item scale of conservatism that is concise, that is modern in its conceptualisation, and that includes both social and economic conservatism subscales. In this paper the 12-Item Social and Economic Conservatism Scale (SECS) is proposed and validated to help fill this gap. The SECS is suggested to be an important and useful tool for researchers working in political psychology

    Association of Glomerular Filtration Rate with High-Sensitivity Cardiac Troponin T in a Community-Based Population Study in Beijing

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    BACKGROUND: Reduced renal function is an independent risk factor for cardiovascular disease mortality, and persistently elevated cardiac troponin T (cTnT) is frequently observed in patients with end-stage renal disease. In the general population the relationship between renal function and cTnT levels may not be clear because of the low sensitivity of the assay. In this study, we investigated the level of cTnT using a highly sensitive assay (hs-cTnT) and evaluated the association of estimated glomerular filtration rate (eGFR) with detectable hs-cTnT levels in a community-based population. METHODS: The serum hs-cTnT levels were measured in 1365 community dwelling population aged ≥45 years in Beijing, China. eGFR was determined by the Chinese modifying modification of diet in renal disease (C-MDRD) equation. RESULTS: With the highly sensitive assay, cTnT levels were detectable (≥3pg/mL) in 744 subjects (54.5%). The result showed that eGFR was associated with Log hs-cTnT (r = -0.14, P<0.001). After adjustment for the high predicted Framingham Coronary Heart Disease (CHD) risk (10-year risk >20%) and other prognostic indicators, moderate to severe reduced eGFR was independently associated with detectable hs-cTnT, whereas normal to mildly reduced eGFR was not independently associated with detectable hs-cTnT. In addition, after adjustment for other risk factors, the high predicted Framingham CHD risk was associated with detectable hs-cTnT in the subjects with different quartile levels of eGFR. CONCLUSION: The levels of hs-cTnT are detectable in a community-based Chinese population and low eGFR is associated with detectable hs-cTnT. Moreover, eGFR and high predicted Framingham CHD risk are associated with detectable hs-cTnT in subjects with moderate-to-severe reduced renal function

    Lentiviral gene therapy for X-linked chronic granulomatous disease

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    Chronic granulomatous disease (CGD) is a rare inherited disorder of phagocytic cells. We report the initial results of nine severely affected X-linked CGD (X-CGD) patients who received ex vivo autologous CD34+ hematopoietic stem and progenitor cell-based lentiviral gene therapy following myeloablative conditioning in first-in-human studies (trial registry nos. NCT02234934 and NCT01855685). The primary objectives were to assess the safety and evaluate the efficacy and stability of biochemical and functional reconstitution in the progeny of engrafted cells at 12 months. The secondary objectives included the evaluation of augmented immunity against bacterial and fungal infection, as well as assessment of hematopoietic stem cell transduction and engraftment. Two enrolled patients died within 3 months of treatment from pre-existing comorbidities. At 12 months, six of the seven surviving patients demonstrated stable vector copy numbers (0.4–1.8 copies per neutrophil) and the persistence of 16–46% oxidase-positive neutrophils. There was no molecular evidence of either clonal dysregulation or transgene silencing. Surviving patients have had no new CGD-related infections, and six have been able to discontinue CGD-related antibiotic prophylaxis. The primary objective was met in six of the nine patients at 12 months follow-up, suggesting that autologous gene therapy is a promising approach for CGD patients

    Understanding the (non-)Use of Societal Wellbeing Indicators in National Policy Development : What Can We Learn from Civil Servants? A UK Case Study

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    Gross Domestic Product is often used as a proxy for societal well-being in the context of policy development. Its shortcomings in this context are, however, well documented, and numerous alternative indicator sets have been developed. Despite this, there is limited evidence of widespread use of these alternative indicator sets by people working in policy areas relevant to societal wellbeing. Civil servants are an important group of indicator end-users. Better understanding their views concerning measuring societal wellbeing can support wider discussions about what factors determine indicator use and influence in policy decision-making. Taking the UK as a case study, we ask what views exist among civil servants in the UK about measuring societal well-being? To answer this question, we used a bootstrapped Q methodology, interviewing 20 civil servants to elicit their views about measuring societal well-being. Three distinct discourses emerged from our analysis: one that was concerned about the consequences of ignoring natural, social and human capital in decision making; one that emphasised opportunity and autonomy as key determinants of well-being; and one that focused on the technical aspects of measuring societal well-being. Each of these discourses has direct implications for the way that we integrate societal wellbeing into policy making and highlights the potential benefits of including end-users in indicator development and strategy
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