465 research outputs found

    Heterodyne Receiver for Origins

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    The Heterodyne Receiver for Origins (HERO) is the first detailed study of a heterodyne focal plane array receiver for space applications. HERO gives the Origins Space Telescope the capability to observe at very high spectral resolution (R = 107) over an unprecedentedly large far-infrared (FIR) wavelengths range (111 to 617 μm) with high sensitivity, with simultaneous dual polarization and dual-frequency band operation. The design is based on prior successful heterodyne receivers, such as Heterodyne Instrument for the Far-Infrared /Herschel, but surpasses it by one to two orders of magnitude by exploiting the latest technological developments. Innovative components are used to keep the required satellite resources low and thus allowing for the first time a convincing design of a large format heterodyne array receiver for space. HERO on Origins is a unique tool to explore the FIR universe and extends the enormous potential of submillimeter astronomical spectroscopy into new areas of astronomical research

    Atypical emotional anticipation in high-functioning autism

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    "Background: Understanding and anticipating others’ mental or emotional states relies on the processing of social cues, such as dynamic facial expressions. Individuals with high-functioning autism (HFA) may process these cues differently from individuals with typical development (TD) and purportedly use a ‘mechanistic’ rather than a ‘mentalistic’ approach, involving rule- and contingency-based interpretations of the stimuli. The study primarily aimed at examining whether the judgments of facial expressions made by individuals with TD and HFA would be similarly affected by the immediately preceding dynamic perceptual history of that face. A second aim was to explore possible differences in the mechanisms underpinning the perceptual judgments in the two groups. Methods: Twenty-two adults with HFA and with TD, matched for age, gender and IQ, were tested in three experiments in which dynamic, ‘ecologically valid’ offsets of happy and angry facial expressions were presented. Participants evaluated the expression depicted in the last frame of the video clip by using a 5-point scale ranging from slightly angry via neutral to slightly happy. Specific experimental manipulations prior to the final facial expression of the video clip allowed examining contributions of bottom-up mechanisms (sequential contrast/ context effects and representational momentum) and a top-down mechanism (emotional anticipation) to distortions in the perception of the final expression. Results: In experiment 1, the two groups showed a very similar perceptual bias for the final expression of joy-to-neutral and anger-to-neutral videos (overshoot bias). In experiment 2, a change in the actor’s identity during the clip removed the bias in the TD group, but not in the HFA group. In experiment 3, neutral-to-joy/anger-to-neutral sequences generated an undershoot bias (opposite to the overshoot) in the TD group, whereas no bias was observed in the HFA group. Conclusions: We argue that in TD individuals the perceptual judgments of other’s facial expressions were underpinned by an automatic emotional anticipation mechanism. In contrast, HFA individuals were primarily influenced by visual features, most notably the contrast between the start and end expressions, or pattern extrapolation. We critically discuss the proposition that automatic emotional anticipation may be induced by motor simulation of the perceived dynamic facial expressions and discuss its implications for autism.

    Discontinuation of alpha-blocker therapy in men with lower urinary tract symptoms:a systematic review and meta-analysis

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    OBJECTIVES: We aimed to synthesise the available data for the effect of stopping alpha-blocker therapy among men with lower urinary tract symptoms. The focus was on symptom, uroflowmetry and quality of life outcomes, but we also reviewed the adverse events (AEs) and the number of patients who restarted therapy.DATA SOURCES: We searched MEDLINE/PubMed, EMBASE/Ovid and The Cochrane Central Register of Controlled Trials from inception to May 2018.ELIGIBILITY CRITERIA: We selected studies regardless of study design in which men were treated with an alpha-blocker for at least 3 months and in which the effects of alpha-blocker discontinuation were subsequently studied. Only controlled trials were used for the primary objective.DATA EXTRACTION AND SYNTHESIS: Two reviewers independently extracted data and assessed the risk of bias for the controlled studies only using the Cochrane Collaboration's tool for assessing risk of bias. Data were pooled using random-effects meta-analyses.RESULTS: We identified 10 studies (1081 participants) assessing the primary objective. Six studies (733 participants) assessed differences in AEs between continuation and discontinuation, and six studies (501 participants) reported the numbers of subjects that restarted treatment after discontinuation. No studies in primary care were identified. After discontinuing monotherapy, symptom scores increased and peak flow rates decreased at 3 and 6 months, but not at 12 months; however, neither parameter changed when alpha-blockers were stopped during combination therapy. Small differences in post-void residual volumes and quality of life scores were considered clinically irrelevant. We also found that 0%-49% of patients restarted after stopping alpha-blocker therapy and that AEs did not increase with discontinuation.CONCLUSIONS: Discontinuing alpha-blocker monotherapy leads to a worsening compared with continuing therapy. Discontinuing the alpha-blocker after combination therapy had no significant effects on outcomes in either the short or long term. Discontinuation may be appropriate for the frail, elderly or those with concomitant illness or polypharmacy. However, studies in primary care are lacking.PROSPERO REGISTRATION NUMBER: CRD42016032648.</p

    Faecal haemoglobin and faecal calprotectin as indicators of bowel disease in patients presenting to primary care with bowel symptoms

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    OBJECTIVE: In primary care, assessing which patients with bowel symptoms harbour significant disease (cancer, higher-risk adenoma or IBD) is difficult. We studied the diagnostic accuracies of faecal haemoglobin (FHb) and faecal calprotectin (FC) in a cohort of symptomatic patients. DESIGN: From October 2013 to March 2014, general practitioners were prompted to request FHb and FC when referring patients with bowel symptoms to secondary care. Faecal samples were analysed for haemoglobin (EIKEN OC-Sensor io) and calprotectin (BÜHLMANN Calprotectin ELISA). Patients triaged to endoscopy were investigated within 6 weeks. All clinicians and endoscopists were blind to the faecal test results. The diagnostic accuracies of FHb and FC for identification of significant bowel disease were assessed. RESULTS: 1043 patients returned samples. FHb was detectable in 57.6% (median 0.4 µg/g, 95% CI 0.4 to 0.8; range 0–200). FC at 50 µg/g or above was present in 60.0%. 755 patients (54.6% women, median age 64 years (range 16–90, IQR 52–73)) returned samples and completed colonic investigations. 103 patients had significant bowel disease; the negative predictive values of FHb for colorectal cancer, higher-risk adenoma and IBD were 100%, 97.8% and 98.4%, respectively. Using cut-offs of detectable FHb and/or 200 µg/g FC detected two further cases of IBD, one higher-risk adenoma and no additional cancers. CONCLUSIONS: In primary care, undetectable FHb is a good ‘rule-out’ test for significant bowel disease and could guide who requires investigation

    KRAB-Induced Heterochromatin Effectively Silences PLOD2 Gene Expression in Somatic Cells and is Resilient to TGFβ1 Activation

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    Epigenetic editing, an emerging technique used for the modulation of gene expression in mammalian cells, is a promising strategy to correct disease-related gene expression. Although epigenetic reprogramming results in sustained transcriptional modulation in several in vivo models, further studies are needed to develop this approach into a straightforward technology for effective and specific interventions. Important goals of current research efforts are understanding the context-dependency of successful epigenetic editing and finding the most effective epigenetic effector(s) for specific tasks. Here we tested whether the fibrosis- and cancer-associated PLOD2 gene can be repressed by the DNA methyltransferase M.SssI, or by the non-catalytic Krüppel associated box (KRAB) repressor directed to the PLOD2 promoter via zinc finger- or CRISPR-dCas9-mediated targeting. M.SssI fusions induced de novo DNA methylation, changed histone modifications in a context-dependent manner, and led to 50%-70% reduction in PLOD2 expression in fibrotic fibroblasts and in MDA-MB-231 cancer cells. Targeting KRAB to PLOD2 resulted in the deposition of repressive histone modifications without DNA methylation and in almost complete PLOD2 silencing. Interestingly, both long-term TGFβ1-induced, as well as unstimulated PLOD2 expression, was completely repressed by KRAB, while M.SssI only prevented the TGFβ1-induced PLOD2 expression. Targeting transiently expressed dCas9-KRAB resulted in sustained PLOD2 repression in HEK293T and MCF-7 cells. Together, these findings point to KRAB outperforming DNA methylation as a small potent targeting epigenetic effector for silencing TGFβ1-induced and uninduced PLOD2 expression

    The Mitochondrial Epigenome:An Unexplored Avenue to Explain Unexplained Myopathies?

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    Mutations in either mitochondrial DNA (mtDNA) or nuclear genes that encode mitochondrial proteins may lead to dysfunctional mitochondria, giving rise to mitochondrial diseases. Some mitochondrial myopathies, however, present without a known underlying cause. Interestingly, methylation of mtDNA has been associated with various clinical pathologies. The present study set out to assess whether mtDNA methylation could explain impaired mitochondrial function in patients diagnosed with myopathy without known underlying genetic mutations. Enhanced mtDNA methylation was indicated by pyrosequencing for muscle biopsies of 14 myopathy patients compared to four healthy controls, at selected cytosines in the Cytochrome B (CYTB) gene, but not within the displacement loop (D-loop) region. The mtDNA methylation patterns of the four healthy muscle biopsies were highly consistent and showed intriguing tissue-specific differences at particular cytosines with control skin fibroblasts cultured in vitro. Within individual myopathy patients, the overall mtDNA methylation pattern correlated well between muscle and skin fibroblasts. Despite this correlation, a pilot analysis of four myopathy and five healthy fibroblast samples did not reveal a disease-associated difference in mtDNA methylation. We did, however, detect increased expression of solute carrier family 25A26 (SLC25A26), encoding the importer of S-adenosylmethionine, together with enhanced mtDNA copy numbers in myopathy fibroblasts compared to healthy controls. To confirm that pyrosequencing indeed reflected DNA methylation and not bisulfite accessibility, mass spectrometry was employed. Although no myopathy-related differences in total amount of methylated cytosines were detected at this stage, a significant contribution of contaminating nuclear DNA (nDNA) was revealed, and steps to improve enrichment for mtDNA are reported. In conclusion, in this explorative study we show that analyzing the mitochondrial genome beyond its sequence opens novel avenues to identify potential molecular biomarkers assisting in the diagnosis of unexplained myopathies

    The effect of piston diameter in primary stapes surgery on surgical success

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    PURPOSE: To evaluate the effect of piston diameter in patients undergoing primary stapes surgery on audiometric results and postoperative complications. METHODS: A retrospective single-center cohort study was performed. Adult patients who underwent primary stapes surgery between January 2013 and April 2022 and received a 0.4-mm-diameter piston or a 0.6-mm-diameter piston were included. The primary and secondary outcomes were pre- and postoperative pure-tone audiometry, pre- and postoperative speech audiometry, postoperative complications, intraoperative anatomical difficulties, and the need for revision stapes surgery. The pure-tone audiometry included air conduction, bone conduction, and air-bone gap averaged over 0.5, 1, 2 and 3 kHz. RESULTS: In total, 280 otosclerosis patients who underwent 321 primary stapes surgeries were included. The audiometric outcomes were significantly better in the 0.6 mm group compared to the 0.4 mm group in terms of gain in air conduction (median = 24 and 20 dB, respectively), postoperative air-bone gap (median = 7.5 and 9.4 dB, respectively), gain in air-bone gap (median = 20.0 and 18.1 dB, respectively), air-bone gap closure to 10 dB or less (75% and 59%, respectively) and 100% speech reception (median = 75 and 80 dB, respectively). We found no statistically significant difference in postoperative dizziness, postoperative complications and the need for revision stapes surgery between the 0.4 and 0.6 mm group. The incidence of anatomical difficulties was higher in the 0.4 mm group. CONCLUSION: The use of a 0.6-mm-diameter piston during stapes surgery seems to provide better audiometric results compared to a 0.4-mm-diameter piston, and should be the preferred piston size in otosclerosis surgery. We found no statistically significant difference in postoperative complications between the 0.4- and 0.6-mm-diameter piston. Based on the results, we recommend always using a 0.6-mm-diameter piston during primary stapes surgery unless anatomical difficulties do not allow it

    Polarisation Observations of VY Canis Majoris Water Vapour 5{32}-4{41} 620.701 GHz Maser Emission with HIFI

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    CONTEXT: Water vapour maser emission from evolved oxygen-rich stars remains poorly understood. Additional observations, including polarisation studies and simultaneous observation of different maser transitions may ultimately lead to greater insight. AIMS: We have aimed to elucidate the nature and structure of the VY CMa water vapour masers in part by observationally testing a theoretical prediction of the relative strengths of the 620.701 GHz and the 22.235 GHz maser components of ortho water vapour. METHODS: In its high-resolution mode (HRS) the Herschel Heterodyne Instrument for the Infrared (HIFI) offers a frequency resolution of 0.125 MHz, corresponding to a line-of-sight velocity of 0.06 km/s, which we employed to obtain the strength and linear polarisation of maser spikes in the spectrum of VY CMa at 620.701 GHz. Simultaneous ground based observations of the 22.235 GHz maser with the Max-Planck-Institut f\"ur Radioastronomie 100-meter telescope at Effelsberg, provided a ratio of 620.701 GHz to 22.235 GHz emission. RESULTS:We report the first astronomical detection to date of water vapour maser emission at 620.701 GHz. In VY CMa both the 620.701 and the 22.235 GHz polarisation are weak. At 620.701 GHz the maser peaks are superposed on what appears to be a broad emission component, jointly ejected asymmetrically from the star. We observed the 620.701 GHz emission at two epochs 21 days apart, both to measure the potential direction of linearly polarised maser components and to obtain a measure of the longevity of these components. Although we do not detect significant polarisation levels in the core of the line, they rise up to approximately 6% in its wings

    Prevalence of cognitive complaints and impairment in patients with Chronic Subdural Hematoma and recovery after treatment:a systematic review

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    BACKGROUND: Chronic Subdural Hematoma (CSDH) is a frequently occurring neurological disease associated with older age and use of anticoagulants. Symptoms vary from headaches to coma, but also cognitive deficits can be present. However, exact prevalence and severity of cognitive deficits in CSDH are still unknown. OBJECTIVE: In this systematic review, we aim to assess cognitive status of patients with CSDH, at presentation and after treatment. METHODS: Pubmed, Embase and Psyqinfo, were searched for articles concerning cognition in CSDH. We divided cognition changes into subjective cognitive deficit (Cognitive Complaints: CC) and objective cognitive deficit (Cognitive Impairment: CI). Two reviewers independently selected studies for inclusion and subsequently extracted data. Quality assessment was done by means of the Newcastle-Ottowa Scale. Reported prevalence of CC and CI was pooled with random effects meta-analysis. RESULTS: Out of 768 identified references, 20 met inclusion criteria. Estimated prevalence of CC and CI in CSDH at presentation was 45% (95% CI: 36% to 54%). Four studies concerned a prospective evaluation of the effect of surgical treatment on cognition. These proved to be of fair to good quality after quality assessment. The estimated pre-treatment prevalence of objectified cognitive impairment was 61% (95% CI: 51% to 70%) decreasing to 18% (95% CI: 8% to 32%) post-surgery Conclusion: From this review it can be concluded that CC and CI are very common in CSDH with a tendency to improve after treatment. Therefore, we underline the importance of increased attention to cognitive status of these patients, with proper testing methods and treatment-testing intervals
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