459 research outputs found

    Evidence against AMPA receptor-lacking glutamatergic synapses in the superficial dorsal horn of the rat spinal cord

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    Pure NMDA receptor (NMDAr)-mediated EPSCs, thought to correspond to "silent" glutamatergic synapses that lack AMPA receptors (AMPArs), have been observed in superficial spinal dorsal horn of neonatal but not adult rats. Recent anatomical studies suggest that AMPArs are present at virtually all glutamatergic synapses in this region in adults. We used antigen retrieval to examine colocalization of AMPArs and PSD-95 (a marker for glutamatergic synapses) in laminae I–II of neonatal and adult rats. We found a high degree of colocalization in all cases, which suggests that AMPArs are present in the great majority of glutamatergic synapses even in neonatal animals. We therefore reexamined evidence for silent synapses by performing blind whole-cell recordings from superficial dorsal horn neurons in slices from neonatal or adult rats, with focal stimulation to activate glutamatergic synapses. On some occasions in both neonatal (10 of 109, 9%) and adult (9 of 77, 12%) slices, NMDAr-mediated EPSCs were observed when the holding potential was raised to +50 mV at a stimulus strength that had failed to evoke AMPAr-mediated EPSCs. However, in all cases tested, AMPAr-mediated EPSCs were then observed when the cell was returned to –70 mV; this and other properties of the EPSCs suggest that they do not represent genuine silent synapses. When compared with previous findings, our results indicate that the appearance of silent synapses depends on experimental protocol. This suggests that pure NMDAr-mediated EPSCs seen in previous studies do not correspond to AMPAr-lacking synapses but result from another mechanism, for example, loss of labile AMPArs from recently formed synapses

    RAPID THICK STRIP CASTING - CONTINUOUS CASTING WITH MOVING MOULDS

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    Moving mould for the future… Due to mechanical reasons, conventional lubricated oscillating moulds limitthe casting velocity. If the friction in the mould grows too strongly, the thin strand shell can tear, in a worstcase followed by a breakout. However these constraints are not applicable to moving moulds.RTSC (Rapid Thick Strip Casting) is an innovative concept for the production of hot strip. The particularinnovation of the mechanism consists in replacing the stationary oscillating mould with a mould performinga caterpillar motion. A new mould design is able to eliminate former failures and problems. The key factor inthe new design consists of a parallelogram-shaped strand cross section. Straight below the caterpillar-mould, ashaping machine is placed with a secondary cooling zone. This is where the conventional rectangular shape isformed by inline-shaping with liquid core.RTSC is a new technology offering the option of high productivity. Studies indicate that a casting speed ina range of 20 to 30 m/min at a final as-cast cross section of e.g. 20 mm x 1600 mm is possible. The strandwidth is easily adjustable and the final product only requires low metal forming degrees in comparison toconventional slabs

    Hypothyroidism and type d personality:Results from E-MPATHY, a cross-sectional international online patient survey

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    ContextBetween 10% and 15% of people with hypothyroidism experience persistent symptoms, despite achieving biochemical euthyroidism.The underlying causes are unclear. Type D personality (a vulnerability factor for general psychological distress) is associated with poor healthstatus and symptom burden but has not been studied in people with hypothyroidism.ObjectiveTo investigate type D personality in hypothyroidism and explore associations with other characteristics and patient-reported outcomes.DesignMultinational, cross-sectional survey.SettingOnline.ParticipantsIndividuals with self-reported, treated hypothyroidism.InterventionQuestionnaire.Main Outcome MeasuresType D personality and associations with baseline characteristics, control of the symptoms of hypothyroidism bymedication, satisfaction with care and treatment of hypothyroidism, impact of hypothyroidism on everyday living.ResultsA total of 3915 responses were received, 3523 of which were valid. The prevalence of type D personality was 54.2%. Statisticallysignificant associations were found between type D personality and several respondent characteristics (age, marital status, ethnicity,household income, comorbidities, type of treatment for hypothyroidism, most recent TSH level), anxiety, depression, somatization, poorcontrol of the symptoms of hypothyroidism by medication, dissatisfaction with care and treatment of hypothyroidism, and a negative impactof hypothyroidism on everyday living).DiscussionOur study found a high prevalence of type D personality among people with hypothyroidism who responded to the survey. Type Dpersonality may be an important determinant of dissatisfaction with treatment and care among people with hypothyroidism. Our findings requireindependent confirmation. Close collaboration between the disciplines of thyroidology and psychology is likely to be key in progressing ourunderstanding in this area

    Testing one-body density functionals on a solvable model

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    There are several physically motivated density matrix functionals in the literature, built from the knowledge of the natural orbitals and the occupation numbers of the one-body reduced density matrix. With the help of the equivalent phase-space formalism, we thoroughly test some of the most popular of those functionals on a completely solvable model.Comment: Latex, 16 pages, 4 figure

    Coherent States of the q--Canonical Commutation Relations

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    For the qq-deformed canonical commutation relations a(f)a(g)=(1q)f,g1+qa(g)a(f)a(f)a^\dagger(g) = (1-q)\,\langle f,g\rangle{\bf1}+q\,a^\dagger(g)a(f) for f,gf,g in some Hilbert space H{\cal H} we consider representations generated from a vector Ω\Omega satisfying a(f)Ω=f,ϕΩa(f)\Omega=\langle f,\phi\rangle\Omega, where ϕH\phi\in{\cal H}. We show that such a representation exists if and only if ϕ1\Vert\phi\Vert\leq1. Moreover, for ϕ<1\Vert\phi\Vert<1 these representations are unitarily equivalent to the Fock representation (obtained for ϕ=0\phi=0). On the other hand representations obtained for different unit vectors ϕ\phi are disjoint. We show that the universal C*-algebra for the relations has a largest proper, closed, two-sided ideal. The quotient by this ideal is a natural qq-analogue of the Cuntz algebra (obtained for q=0q=0). We discuss the Conjecture that, for d<d<\infty, this analogue should, in fact, be equal to the Cuntz algebra itself. In the limiting cases q=±1q=\pm1 we determine all irreducible representations of the relations, and characterize those which can be obtained via coherent states.Comment: 19 pages, Plain Te

    Elastic modulus of multi-walled carbon nanotubes produced by catalytic chemical vapour deposition

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    Carbon nanotubes (CNTs) are ideal structures for use as reinforcement fibres in composite materials, due to their extraordinary mechanical properties, in particular high Young's modulus (E∼1TPa). Usually the high value of E is taken as granted for all types of carbon CNTs. Here we demonstrate that multi-walled carbon nanotubes (MWCNTs) produced by catalytic chemical vapour deposition (CCVD) have low moduli (E<100GPa) independently of their growth conditions. We attribute this to the presence of structural defects. Additional high-temperature annealing failed to improve the mechanical properties. This study urges a better control of the growth process in order to obtain high strength CCVD grown MWCNTs suitable for reinforcement in large-scale industrial application

    Application of spatio-temporal data in site-specific maize yield prediction with machine learning methods

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    In order to meet the requirements of sustainability and to determine yield drivers and limiting factors, it is now more likely that traditional yield modelling will be carried out using artificial intelligence (AI). The aim of this study was to predict maize yields using AI that uses spatio-temporal training data. The paper has advanced a new method of maize yield prediction, which is based on spatio-temporal data mining. To find the best solution, various models were used: counter-propagation artificial neural networks (CP-ANNs), XY-fused Querynetworks (XY-Fs), supervised Kohonen networks (SKNs), neural networks with Rectangular Linear Activations (ReLU), extreme gradient boosting (XGBoost), support-vector machine (SVM), and different subsets of the independent variables in five vegetation periods. Input variables for modelling included: soil parameters (pH, P2O5, K2O, Zn, clay content, ECa, draught force, Cone index), micro-relief averages, and meteorological parameters for the 63 treatment units in a 15.3 ha research field. The best performing method (XGBoost) reached 92.1% and 95.3% accuracy on the training and the test sets. Additionally, a novel method was introduced to treat individual units in a lattice system. The lattice-based smoothing performed an additional increase in Area under the curve (AUC) to 97.5% over the individual predictions of the XGBoost model. The models were developed using 48 different subsets of variables to determine which variables consistently contributed to prediction accuracy. By comparing the resulting models, it was shown that the best regression model was Extreme Gradient Boosting Trees, with 92.1% accuracy (on the training set). In addition, the method calculates the influence of the spatial distribution of site-specific soil fertility on maize grain yields. This paper provides a new method of spatio-temporal data analyses, taking the most important influencing factors on maize yields into account

    Downregulation of endothelial plexin A4 under inflammatory conditions impairs vascular integrity

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    Objective: Besides hyperlipidemia, inflammation is an important determinant in the initiation and the progression of atherosclerosis. As Neuroimmune Guidance Cues (NGCs) are emerging as regulators of atherosclerosis, we set out to investigate the expression and function of inflammation-regulated NGCs.Methods and results: NGC expression in human monocytes and endothelial cells was assessed using a publicly available RNA dataset. Next, the mRNA levels of expressed NGCs were analyzed in primary human monocytes and endothelial cells after stimulation with IL1 beta or TNF alpha. Upon stimulation a total of 14 and 19 NGCs in monocytes and endothelial cells, respectively, were differentially expressed. Since plexin A4 (PLXNA4) was strongly downregulated in endothelial cells under inflammatory conditions, the role of PLXNA4 in endothelial function was investigated. Knockdown of PLXNA4 in endothelial cells markedly impaired the integrity of the monolayer leading to more elongated cells with an inflammatory phenotype. In addition, these cells showed an increase in actin stress fibers and decreased cell-cell junctions. Functional assays revealed decreased barrier function and capillary network formation of the endothelial cells, while vascular leakage and trans-endothelial migration of monocytes was increased.Conclusion: The current study demonstrates that pro-inflammatory conditions result in differential expression of NGCs in endothelial cells and monocytes, both culprit cell types in atherosclerosis. Specifically, endothelial PLXNA4 is reduced upon inflammation, while PLXNA4 maintains endothelial barrier function thereby preventing vascular leakage of fluids as well as cells. Taken together, PLXNA4 may well have a causal role in atherogenesis that deserves further investigation.Nephrolog

    Measurement of the Strong Coupling alpha s from Four-Jet Observables in e+e- Annihilation

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    Data from e+e- annihilation into hadrons at centre-of-mass energies between 91 GeV and 209 GeV collected with the OPAL detector at LEP, are used to study the four-jet rate as a function of the Durham algorithm resolution parameter ycut. The four-jet rate is compared to next-to-leading order calculations that include the resummation of large logarithms. The strong coupling measured from the four-jet rate is alphas(Mz0)= 0.1182+-0.0003(stat.)+-0.0015(exp.)+-0.0011(had.)+-0.0012(scale)+-0.0013(mass) in agreement with the world average. Next-to-leading order fits to the D-parameter and thrust minor event-shape observables are also performed for the first time. We find consistent results, but with significantly larger theoretical uncertainties.Comment: 25 pages, 15 figures, Submitted to Euro. Phys. J.

    White paper on guidelines concerning enteric nervous system stem cell therapy for enteric neuropathies.

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    Over the last 20 years, there has been increasing focus on the development of novel stem cell based therapies for the treatment of disorders and diseases affecting the enteric nervous system (ENS) of the gastrointestinal tract (so-called enteric neuropathies). Here, the idea is that ENS progenitor/stem cells could be transplanted into the gut wall to replace the damaged or absent neurons and glia of the ENS. This White Paper sets out experts' views on the commonly used methods and approaches to identify, isolate, purify, expand and optimize ENS stem cells, transplant them into the bowel, and assess transplant success, including restoration of gut function. We also highlight obstacles that must be overcome in order to progress from successful preclinical studies in animal models to ENS stem cell therapies in the clinic
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