860 research outputs found

    Capture of Mouse and Human Stem Cells with Features of Formative Pluripotency.

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    Pluripotent cells emerge as a naive founder population in the blastocyst, acquire capacity for germline and soma formation, and then undergo lineage priming. Mouse embryonic stem cells (ESCs) and epiblast-derived stem cells (EpiSCs) represent the initial naive and final primed phases of pluripotency, respectively. Here, we investigate the intermediate formative stage. Using minimal exposure to specification cues, we derive stem cells from formative mouse epiblast. Unlike ESCs or EpiSCs, formative stem (FS) cells respond directly to germ cell induction. They colonize somatic tissues and germline in chimeras. Whole-transcriptome analyses show similarity to pre-gastrulation formative epiblast. Signal responsiveness and chromatin accessibility features reflect lineage capacitation. Furthermore, FS cells show distinct transcription factor dependencies, relying critically on Otx2. Finally, FS cell culture conditions applied to human naive cells or embryos support expansion of similar stem cells, consistent with a conserved staging post on the trajectory of mammalian pluripotency.The Cambridge Stem Cell Institute receives core funding from Wellcome and the Medical Research Council. This research was funded by the Biotechnology and Biological Sciences Research Council and the Medical Research Council of the United Kingdom. AS is a Medical Research Council Professor

    Comparison of the α and β isomeric forms of the detergent n-dodecyl-D-maltoside for solubilizing photosynthetic complexes from pea thylakoid membranes

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    AbstractMild non-ionic detergents are indispensable in the isolation of intact integral membrane proteins and protein-complexes from biological membranes. Dodecylmaltoside (DM) belongs to this class of detergents being a glucoside-based surfactant with a bulky hydrophilic head group composed of two sugar rings and a non-charged alkyl glycoside chain. Two isomers of this molecule exist, differing only in the configuration of the alkyl chain around the anomeric center of the carbohydrate head group, axial in α-DM and equatorial in β-DM. In this paper, we have investigated the solubilizing properties of α-DM and β-DM on the isolation of photosynthetic complexes from pea thylakoids membranes maintaining their native architecture of stacked grana and stroma lamellae. Exposure of these stacked thylakoids to a single step treatment with increasing concentrations (5–100mM) of α-DM or β-DM resulted in a quick partial or complete solubilization of the membranes. Regardless of the isomeric form used: 1) at the lowest DM concentrations only a partial solubilization of thylakoids was achieved, giving rise to the release of mainly small protein complexes mixed with membrane fragments enriched in PSI from stroma lamellae; 2) at concentrations above 30mM a complete solubilization occurred with the further release of high molecular weight protein complexes identified as dimeric PSII, PSI-LHCI and PSII–LHCII supercomplexes. However, at concentrations of detergent which fully solubilized the thylakoids, the α and β isomeric forms of DM exerted a somewhat different solubilizing effect on the membranes: higher abundance of larger sized PSII–LHCII supercomplexes retaining a higher proportion of LHCII and lower amounts of PSI–LHCI intermediates were observed in α-DM treated membranes, reflecting the mildness of α-DM compared with its isomer. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial

    Determinants of treatment plan implementation in multidisciplinary team meetings for patients with chronic diseases: a mixed-methods study.

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    This is the final version of the article. Available from the publisher via the DOI in this record.OBJECTIVE: Multidisciplinary team (MDT) meetings are assumed to produce better decisions and are extensively used to manage chronic disease in the National Health Service (NHS). However, evidence for their effectiveness is mixed. Our objective was to investigate determinants of MDT effectiveness by examining factors influencing the implementation of MDT treatment plans. This is a proxy measure of effectiveness, because it lies on the pathway to improvements in health, and reflects team decision making which has taken account of clinical and non-clinical information. Additionally, this measure can be compared across MDTs for different conditions. METHODS: We undertook a prospective mixed-methods study of 12 MDTs in London and North Thames. Data were collected by observation of 370 MDT meetings, interviews with 53 MDT members, and from 2654 patient medical records. We examined the influence of patient-related factors (disease, age, sex, deprivation, whether their preferences and other clinical/health behaviours were mentioned) and MDT features (as measured using the 'Team Climate Inventory' and skill mix) on the implementation of MDT treatment plans. RESULTS: The adjusted odds (or likelihood) of implementation was reduced by 25% for each additional professional group represented at the MDT meeting. Implementation was more likely in MDTs with clear goals and processes and a good 'Team Climate' (adjusted OR 1.96; 95% CI 1.15 to 3.31 for a unit increase in Team Climate Inventory (TCI) score). Implementation varied by disease category, with the lowest adjusted odds of implementation in mental health teams. Implementation was also lower for patients living in more deprived areas (adjusted odds of implementation for patients in the most compared with least deprived areas was 0.60, 95% CI 0.39 to 0.91). CONCLUSIONS: Greater multidisciplinarity is not necessarily associated with more effective decision making. Explicit goals and procedures are also crucial. Decision implementation should be routinely monitored to ensure the equitable provision of care.This project was funded by the NIHR Health Services and Delivery Research programme (project number 09/2001/ 04) and will be published in full in the Health Services and Delivery Research Journal. Further information available at: (http://www.netscc.ac.uk/hsdr/projdetails.php?ref=09-2001-04). In accordance with NIHR regulations, the findings reported here are to be referred to as initial until the NIHR final report has been published. The sponsors of the study had no role in study design, data collection, data analysis, data interpretation, the writing of the report, or the decision to submit the report for publication

    Conceptualising sustainability in UK urban Regeneration: a discursive Formation

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    Despite the wide usage and popular appeal of the concept of sustainability in UK policy, it does not appear to have challenged the status quo in urban regeneration because policy is not leading in its conceptualisation and therefore implementation. This paper investigates how sustainability has been conceptualised in a case-based research study of the regeneration of Eastside in Birmingham, UK, through policy and other documents, and finds that conceptualisations of sustainability are fundamentally limited. The conceptualisation of sustainability operating within urban regeneration schemes should powerfully shape how they make manifest (or do not) the principles of sustainable development. Documents guide, but people implement regeneration—and the disparate conceptualisations of stakeholders demonstrate even less coherence than policy. The actions towards achieving sustainability have become a policy ‘fix’ in Eastside: a necessary feature of urban policy discourse that is limited to solutions within market-based constraints

    Drosophila Insulin Pathway Mutants Affect Visual Physiology and Brain Function Besides Growth, Lipid, and Carbohydrate Metabolism

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    OBJECTIVE—Type 2 diabetes is the most common form of diabetes worldwide. Some of its complications, such as retinop-athy and neuropathy, are long-term and protracted, with an un-clear etiology. Given this problem, genetic model systems, such as in flies where type 2 diabetes can be modeled and studied, offer distinct advantages. RESEARCH DESIGN AND METHODS—We used individual flies, control, and mutant individuals with partial loss-of-function insulin pathway genes. We measured wing size and tested body weight for growth phenotypes, the latter by means of a microbal-ance. We studied total lipid and carbohydrate content, lipids by a reaction in single fly homogenates with vanillin-phosphoric acid, and carbohydrates with an anthrone-sulfuric acid reaction. Cholinesterase activity was measured using the Ellman method in head homogenates from pooled fly heads, and electroretinogram

    Characterization of Patients With Lupus Nephritis Included in a Large Cohort From the Spanish Society of Rheumatology Registry of Patients With Systemic Lupus Erythematosus (RELESSER)

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    The aim of the study was to profile those patients included in the RELESSER registry with histologically proven renal involvement in order to better understand the current state of lupus nephritis (LN) in Spain. RELESSER-TRANS is a multicenter cross-sectional registry with an analytical component. Information was collected from the medical records of patients with systemic lupus erythematosus who were followed at participating rheumatology units. A total of 359 variables including demographic data, clinical manifestations, disease activity, severity, comorbidities, LN outcome, treatments, and mortality were recorded. Only patients with a histological confirmation of LN were included.We performed a descriptive analysis, chi-square or Student?s t tests according to the type of variable and its relationship with LN. Odds ratio and confidence intervals were calculated by using simple logistic regression. LN was histologically confirmed in 1092/3575 patients (30.5%). Most patients were female (85.7%), Caucasian (90.2%), and the mean age at LN diagnosis was 28.4 12.7 years. The risk for LN development was higher in men (M/F:47.85/30.91%, P<0.001), in younger individuals (P<0.001), and in Hispanics (P¼0.03). Complete response to treatment was achieved in 68.3% of patients; 10.35% developed ESRD, which required a kidney transplant in 45% of such cases. The older the patient, the greater was the likelihood of complete response (P<0.001). Recurrences were associated with persistent lupus activity at the time of the last visit (P<0.001) and with ESRD (P<0.001). Thrombotic microangiopathy was a risk factor for ESRD (P¼0.04), as for the necessity of dialysis (P¼0.01) or renal transplantation (P¼0.03). LN itself was a poor prognostic risk factor of mortality (OR 2.4 [1.81?3.22], P<0.001). Patients receiving antimalarials had a significantly lower risk of developing LN (P<0.001) and ESRD (P<0.001), and responded better to specific treatments for LN (P¼0.014). More than two-thirds of the patients with LN from a wide European cohort achieved a complete response to treatment. The presence of positive anti-Sm antibodies was associated with a higher frequency of LN and a decreased rate of complete response to treatment. The use of antimalarials reduced both the risk of developing renal disease and its severity, and contributed to attaining a complete renal response

    Nest site choice by the intertidal spider Desis formidabilis (Araneae: Desidae) and nest utilisation by its hymenopteran egg parasitoid

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    1. Echthrodesis lamorali Masner, 1968 is the only known parasitoid of the eggs of the intertidal rocky shore spider Desis formidabilis O.P. Cambridge 1890 and is endemic to a small area of South Africa. 2. The abundance of spider nests and parasitoid presence were assessed in relation to their in- and between-shore location at multiple sites within the distribution of E. lamorali along the Cape Peninsula (Western Cape, South Africa). 3. Desis formidabilis nests were more abundant in the mid-shore zone than higher up or lower down the shore. Spider population sizes also differed between collection sites, with higher numbers recorded on the cooler western coast of the peninsula. 4. Evidence of parasitoid activity was recorded in 43.31% of the 127 nests and 13.85% of the 592 egg sacs they contained. 5. Where parasitoids gained entry to a spider egg sac, oviposition took place into all of the eggs present. 6. Incidence of wasp activity was positively correlated with spider nest concentration, not with height up the shore, suggesting that both the host and parasitoid are tolerant of salt-water inundation. 7. These results should assist managers of the Table Mountain National Park, in which the full distribution of E. lamorali falls, to better understand this component of rocky shore community dynamics

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration
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