856 research outputs found

    Custom wheat microarray development for analysis of grain quality

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    BACKGROUND: Germline mutations in the SMAD4 gene lead to both juvenile polyposis syndrome and hereditary haemorrhagic telangiectasia (HHT). CASE DESCRIPTION: A 23-year-old man underwent colectomy with ileo-anal pouch anastomosis at the age of 12 due to colorectal juvenile polyposis. At follow-up, recurrent juvenile polyps in the pouch were removed. No gastric polyps were found. The family history was negative for intestinal polyposis. In addition, the patient had recurrent epistaxis. DNA testing revealed a pathogenic SMAD4 mutation: c.1558G>T; p.(Glu520*). Further examination confirmed suspected HHT. CONCLUSION: DNA testing in patients with juvenile polyposis is important for subclassification of this syndrome with implications for the management of patients and family members

    Treatment of psoriasis

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    Psoriasis is a prevalent chronic inflammatory disease. Beyond skin and joint manifestations, psoriasis has numerous associated comorbidities, including metabolic and cardiovascular disease. There are many treatment options available, from topical treatment for mild psoriasis, phototherapy for moderate disease, to systemic therapy or biological agents for severe disease. This article aims to focus on the treatment for the majority of patients where topical agents alone are generally appropriate.http://www.sapj.co.za/index.php/sapjam2021Dental Management Science

    Feedback-control of quantum systems using continuous state-estimation

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    We present a formulation of feedback in quantum systems in which the best estimates of the dynamical variables are obtained continuously from the measurement record, and fed back to control the system. We apply this method to the problem of cooling and confining a single quantum degree of freedom, and compare it to current schemes in which the measurement signal is fed back directly in the manner usually considered in existing treatments of quantum feedback. Direct feedback may be combined with feedback by estimation, and the resulting combination, performed on a linear system, is closely analogous to classical LQG control theory with residual feedback.Comment: 12 pages, multicol revtex, revised and extende

    Molecular imaging of depressive disorders

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    This chapter summarizes findings of a large number of molecular imaging studies in the field of unipolar and bipolar depression (BD). Brain metabolism in depressed unipolar and bipolar patients is generally hypoactive in the middle frontal gyri, the pregenual and posterior anterior cingulate, the superior temporal gyrus, the insula, and the cerebellum, while hyperactivity exists in subcortical (caudate nucleus, thalamus), limbic (amygdala, anterior hippocampus), and medial and inferior frontal regions. Interestingly, after depletion of serotonin or noradrenalin/dopamine in vulnerable (recovered) major depressive disorder (MDD) patients, a similar response pattern in metabolism occurs. Findings on the pre-and postsynaptic dopaminergic system show indications that, at least in subgroups of retarded MDD patients, presynaptic dopaminergic markers may be decreased, while postsynaptic markers may be increased. The findings regarding serotonin synthesis, pre-and postsynaptic imaging can be integrated to a presumable loss of serotonin in MDD, while this remains unclear in BD. This reduction of serotonin and dopamine in MDD was recently summarized in a revised version of the monoamine hypothesis, which focuses more on a dysfunction at the level of the MAO enzyme. This should be addressed further in future studies. Nevertheless, it should be acknowledged that the serotonergic and dopaminergic systems appear adaptive; therefore, it remains difficult to distinguish state and trait abnormalities. Therefore, future longitudinal molecular imaging studies in the same subjects at different clinical mood states (preferably with different tracers and imaging modalities) are needed to clarify whether the observed changes in transporters and receptors are compensatory reactions or reflect different, potentially causal mechanisms. Several suggestions for future developments are also provided at the end of this chapter.</p

    Feedback cooling of a nanomechanical resonator

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    Cooled, low-loss nanomechanical resonators offer the prospect of directly observing the quantum dynamics of mesoscopic systems. However, the present state of the art requires cooling down to the milliKelvin regime in order to observe quantum effects. Here we present an active feedback strategy based on continuous observation of the resonator position for the purpose of obtaining these low temperatures. In addition, we apply this to an experimentally realizable configuration, where the position monitoring is carried out by a single-electron transistor. Our estimates indicate that with current technology this technique is likely to bring the required low temperatures within reach.Comment: 10 pages, RevTex4, 4 color eps figure

    Mirror quiescence and high-sensitivity position measurements with feedback

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    We present a detailed study of how phase-sensitive feedback schemes can be used to improve the performance of optomechanical devices. Considering the case of a cavity mode coupled to an oscillating mirror by the radiation pressure, we show how feedback can be used to reduce the position noise spectrum of the mirror, cool it to its quantum ground state, or achieve position squeezing. Then, we show that even though feedback is not able to improve the sensitivity of stationary position spectral measurements, it is possible to design a nonstationary strategy able to increase this sensitivity.Comment: 25 pages, 11 figure
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