8 research outputs found

    Observation of gravitational waves from the coalescence of a 2.5−4.5 M⊙ compact object and a neutron star

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    Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

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    Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≀0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

    Ultralight vector dark matter search using data from the KAGRA O3GK run

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    Among the various candidates for dark matter (DM), ultralight vector DM can be probed by laser interferometric gravitational wave detectors through the measurement of oscillating length changes in the arm cavities. In this context, KAGRA has a unique feature due to differing compositions of its mirrors, enhancing the signal of vector DM in the length change in the auxiliary channels. Here we present the result of a search for U(1)B−L gauge boson DM using the KAGRA data from auxiliary length channels during the first joint observation run together with GEO600. By applying our search pipeline, which takes into account the stochastic nature of ultralight DM, upper bounds on the coupling strength between the U(1)B−L gauge boson and ordinary matter are obtained for a range of DM masses. While our constraints are less stringent than those derived from previous experiments, this study demonstrates the applicability of our method to the lower-mass vector DM search, which is made difficult in this measurement by the short observation time compared to the auto-correlation time scale of DM

    Feasibility of Objective Seabed Mapping Techniques in a Coastal Tidal Environment (Wadden Sea, Germany)

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    The growing interest in monitoring the marine environment has strongly encouraged governmental agencies and research institutes to undertake seabed mapping programs and stimulated scientific interest in innovative mapping methods and tools. In this study, object-based image analysis was used to map a very shallow tidal inlet, characterized by high sediment variability and intense morphodynamic processes. The aim was to test the feasibility of reproducible mapping approaches within extended mapping programs of complex coastal areas. The study is based on full-coverage, high-resolution bathymetry and reflectivity, calibrated by means of sediment samples. Seafloor segmentation and classification were based on a cluster analysis performed on reflectivity, slope, and ruggedness. Statistics of clusters were extracted and analysed to identify the optimal number of clusters and evaluate the suitability of the clustering process to differentiate different seabed types. Clusters and samples data were joined to create a training and validation dataset for characterizing the seabed and carrying out an accuracy assessment. Misclassifications were explored and referred to three main reasons: (i) The not-perfect correspondence between sediment boundaries of classification systems and boundaries derived from the clustering process; (ii) the geomorphological features of the seabed; and (iii) the position accuracy of samples. The study contributes to testing of the feasibility of objective methods and highlights the importance of joining acoustic, lithological, and geomorphological analysis. It highlights issues and the need to critically analyse the mapping results and improve the accuracy of collected data

    Constipation distinguishes different clinical-biochemical patterns in de novo Parkinson's disease

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    Introduction: Prodromal constipation (PC) at Parkinson's disease (PD) onset may mark a distinct neurodegen-erative trajectory; accordingly, presenting phenotype, biochemical signature, and progression of PD patients with PC (PD + PC) might differ from those without (PDwoPC). We compared the clinical-biochemical profile of de novo PD patients with and without PC, and the respective mid-term progression, to establish the grouping effect of PC. Methods: Motor and non-motor scores were collected at diagnosis in n = 57 PD + PC patients and n = 73 PDwoPC. Paired CSF biomarkers (alpha-synuclein, amyloid and tau peptides, lactate, CSF/serum albumin ratio or AR) were assessed into a smaller sample and n = 46 controls. Clinical progression was estimated as Hoehn and Yahr stage (HY) and levodopa equivalent daily dose (LEDD) change 2.06 +/- 1.35 years after diagnosis. Results: At onset, PD + PC patients had higher HY and MDS-UPDRS-part III scores, and higher CSF AR. PDwoPC had higher Non-Motor Symptoms Scale domain-2 score, and lower CSF alpha-synuclein level. At follow-up, PD + PC had greater LEDD. Conclusions: PC identifies a group of de novo patients with more severe motor impairment, possible blood brain barrier disruption, and greater dopaminergic requirement at mid-term; conversely, de novo PDwoPC patients had prominent fatigue, and pronounced central synucleinopathy

    Table_1_Short-term effects of foot surgery on walking-related pain, function, and satisfaction in patients with Charcot–Marie–Tooth disease: a prospective cohort study.docx

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    IntroductionPatients with Charcot–Marie–Tooth disease (CMT) often suffer from walking-related pain (WRP), muscle weakness, foot deformities, and reduced ankle dorsiflexion (DF), which affects their ability to walk and daily activities. Functional surgery (FS) can restore foot deviations, affecting the loading ability during gait. We assessed the short-term effects of FS in patients with CMT on WRP, foot and ankle structure, and function, along with patients’ perceived improvement.MethodsThis is a prospective cohort study on CMT patients who had undergone FS and rehabilitation. We analyzed the changes after 1 month, focusing on WRP, DF, the center of pressure progression (COPP) during walking, and measures of walking ability. The non-parametric Wilcoxon test was used.ResultsTen patients were included. One month after FS, WRP reduced from 5.5 (IQR = 3.5) to 2 (IQR = 3.5), p = 0.063, with an effect size of 0.615. The highest decrease was found in patients with very high pre-surgical pain levels. DF almost reached 10° for both active and passive movements (p ConclusionFS can be effective in reducing WRP and restoring foot posture in CMT patients in the short-term, which allows them to wear shoes, and leads to a perceived improvement and satisfaction. Lack of improvement in functional skills may be due to muscle weakness typical of CMT. Studies with longer follow-ups may confirm these hypotheses.</p

    Olfactory Neuron Prokineticin-2 as a Potential Target in Parkinson's Disease

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    Objective The objective of this study was to outline the dynamics of prokineticin-2 pathway in relation to clinical-pathological features of Parkinson's disease by examining olfactory neurons of patients. Methods Thirty-eight patients (26 de novo, newly diagnosed) and 31 sex/age-matched healthy controls underwent noninvasive mucosa brushing for olfactory neurons collection, and standard clinical assessment. Gene expression levels of prokineticin-2, prokineticin-2 receptors type 1 and 2, and prokineticin-2-long peptide were measured in olfactory neurons by real-time polymerase chain reaction (PCR); moreover, the prokineticin-2 protein and alpha-synuclein species (total and oligomeric) were quantified by immunofluorescence staining. Results Prokineticin-2 expression was significantly increased in Parkinson's disease. De novo patients had higher prokineticin-2 levels, directly correlated with Movement Disorder Society-Sponsored Revision of the Unified Parkinson Disease Rating Scale (MDS-UPDRS) part III motor score. In addition, oligomeric alpha-synuclein was higher in Parkinson's disease and directly correlated with prokineticin-2 protein levels. Total alpha-synuclein did not differ between patients and controls. Interpretation Prokineticin-2 is a chemokine showing neuroprotective effects in experimental models of Parkinson's disease, but translational proof of its role in patients is still lacking. Here, we used olfactory neurons as the ideal tissue to analyze molecular stages of neurodegeneration in vivo, providing unprecedented evidence that the prokineticin-2 pathway is activated in patients with Parkinson's disease. Specifically, prokineticin-2 expression in olfactory neurons was higher at early disease stages, proportional to motor severity, and associated with oligomeric alpha-synuclein accumulation. These data, consistently with preclinical findings, support prokineticin-2 as a candidate target in Parkinson's disease, and validate reliability of olfactory neurons to reflect pathological changes of the disease. ANN NEUROL 202

    Olfactory neuron substance P is overexpressed in Parkinson's disease reflecting gut dysfunction

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    bstance P (SP) and its cognate Neurokinin receptor 1 (NK1R) are tachykinergic neuroinflammatory mediators widely expressed in the central nervous system, peripheral nervous system, enteric nervous system, and immune cells. The SP/NK1R pathway is activated by several noxious stimuli and triggers a sustained inflammatory response by inducing cytokines release from different cell subtypes. In Parkinson's disease (PD), SP colocalizes with α-synuclein in the central and peripheral structures more prone to degeneration, mostly within the gastrointestinal–nervous ascending system, suggesting a potential role in the disease pathogenesis through inflammation-related mechanisms
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