426 research outputs found

    Target company cross-border effects in acquisitions into the UK

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    We analyse the abnormal returns to target shareholders in crossborder and domestic acquisitions of UK companies. The crossborder effect during the bid month is small (0.84%), although crossborder targets gain significantly more than domestic targets during the months surrounding the bid. We find no evidence for the level of abnormal returns in crossborder acquisitions to be associated with market access or exchange rate effects, and only limited support for an international diversification effect. However, the crossborder effect appears to be associated with significant payment effects, and there is no significant residual crossborder effect once various bid characteristics are controlled for

    Imaging of Uveal Melanoma—Current Standard and Methods in Development

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    Uveal melanoma is the most common primary intraocular malignancy in adults, characterized by an insidious onset and poor prognosis strongly associated with tumor size and the presence of distant metastases, most commonly in the liver. Contrary to most tumor identification, a biopsy followed by a pathological exam is used only in certain cases. Therefore, an early and noninvasive diagnosis is essential to enhance patients’ chances for early treatment. We reviewed imaging modalities currently used in the diagnostics of uveal melanoma, including fundus imaging, ultrasonography (US), optical coherence tomography (OCT), single-photon emission computed tomography (SPECT), fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), fundus autofluorescence (FAF), as well as positron emission tomography/computed tomography (PET/CT) or magnetic resonance imaging (MRI). The principle of imaging techniques is briefly explained, along with their role in the diagnostic process and a summary of their advantages and limitations. Further, the experimental data and the advancements in imaging modalities are explained. We describe UM imaging innovations, show their current usage and development, and explain the possibilities of utilizing such modalities to diagnose uveal melanoma in the future

    Teager–Kaiser energy operator signal conditioning improves EMG onset detection

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    Accurate identification of the onset of muscle activity is an important element in the biomechanical analysis of human movement. The purpose of this study was to determine if inclusion of the Teager–Kaiser energy operator (TKEO) in signal conditioning would increase the accuracy of popular electromyography (EMG) onset detection methods. Three methods, visual determination, threshold-based method, and approximated generalized likelihood ratio were used to estimate the onset of EMG burst with and without TKEO conditioning. Reference signals, with known onset times, were constructed from EMG signals collected during isometric contraction of the vastus lateralis (n = 17). Additionally, vastus lateralis EMG signals (n = 255) recorded during gait were used to evaluate a clinical application of the TKEO conditioning. Inclusion of TKEO in signal conditioning significantly reduced mean detection error of all three methods compared with signal conditioning without TKEO, using artificially generated reference data (13 vs. 98 ms, p < 0.001) and also compared with experimental data collected during gait (55 vs. 124 ms, p < 0.001). In conclusion, addition of TKEO as a step in conditioning surface EMG signals increases the detection accuracy of EMG burst boundaries

    Ancient herpes simplex 1 genomes reveal recent viral structure in Eurasia

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    Human herpes simplex virus 1 (HSV-1), a life-long infection spread by oral contact, today infects a majority of adults globally1, yet no ancient HSV-1 genomes have yet been published. Phylogeographic clustering of sampled diversity into European, pan-Eurasian, and African groups2, 3 has suggested that the virus co-diverged with anatomically modern humans migrating out of Africa4, although a much younger origin has also been proposed5. The lack of ancient HSV-1 genomes, high rates of recombination, and high mobility of humans in the modern era have impeded the understanding of HSV-1’s evolutionary history. Here we present three full ancient European HSV-1 genomes and one partial genome, dating to between the 3rd and 17th century CE, sequenced to up to 9.5× with paired human genomes up to 10.16×. These HSV-1 strains fall within modern Eurasian diversity. We estimate a mean mutation rate of 7.6 × 10-7Introduction Results - Retrieved genomes are likely from typical infections - Demographic history of HSV-1 in a global context Discussion Material and Methods - Ethics statement - Sampling - Generation of aDNA libraries - Sequencing - aDNA authentication - Metagenomic screening - Targeted capture of HSV-1 - Alignment of viral data to the reference sequence - Genotyping - HSV-1 linkage disequilibrium and population genetic analysis - Compilation of comparative HSV data - Preparation of genome sequences - HSV-1 phylogenetic analysis and recombination filtering - Phylogenetic dating - Alignment of human data to the reference sequence and quality control - Genetic sex estimation, mtDNA, and Y haplotyping - Human variant calling and imputation of genotype

    Direct and crossed effects of somatosensory electrical stimulation on motor learning and neuronal plasticity in humans

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    Purpose Sensory input can modify voluntary motor function. We examined whether somatosensory electrical stimulation (SES) added to motor practice (MP) could augment motor learning, interlimb transfer, and whether physiological changes in neuronal excitability underlie these changes. Methods Participants (18-30 years, n = 31) received MP, SES, MP + SES, or a control intervention. Visuomotor practice included 300 trials for 25 min with the right-dominant wrist and SES consisted of weak electrical stimulation of the radial and median nerves above the elbow. Single-and double-pulse transcranial magnetic stimulation (TMS) metrics were measured in the intervention and nonintervention extensor carpi radialis. Results There was 27 % motor learning and 9 % (both p <0.001) interlimb transfer in all groups but SES added to MP did not augment learning and transfer. Corticospinal excitability increased after MP and SES when measured at rest but it increased after MP and decreased after SES when measured during contraction. No changes occurred in intra-cortical inhibition and facilitation. MP did not affect the TMS metrics in the transfer hand. In contrast, corticospinal excitability strongly increased after SES with MP + SES showing sharply opposite of these effects. Conclusion Motor practice and SES each can produce motor learning and interlimb transfer and are likely to be mediated by different mechanisms. The results provide insight into the physiological mechanisms underlying the effects of MP and SES on motor learning and cortical plasticity and show that these mechanisms are likely to be different for the trained and stimulated motor cortex and the non-trained and non-stimulated motor cortex

    Salmonella enterica serotype Virchow associated with human infections in Switzerland: 2004-2009

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    BACKGROUND: Salmonellosis is one of the most important foodborne diseases and a major threat to public health. Salmonella serotype Virchow ranks among the top five serovars in Europe. METHOD: A total of 153 strains isolated from different patients from 2004 through 2009 in Switzerland were further characterized by (i) assessing phenotypic antibiotic resistance profiles using the disk diffusion method and (ii) by genotyping using pulsed-field gel electrophoresis (PFGE) after macrorestriction with XbaI in order to evaluate strain relationship. RESULTS: The relative frequency of S. Virchow among other Salmonella serovars varied between 4th to 8th rank. The annual incidence ranged from 0.45/100'000 in 2004 to 0.40/100'000 in 2009. A total of 48 strains (32%) were resistant to one to 3 antimicrobials, 54 strains (36%) displayed resistance patterns to more than three antibiotics. No trend was identifiable over the years 2004 to 2009. We found a high prevalence (62%) of nalidixic acid resistant strains, suggesting an equally high rate of decreased fluoroqionolone susceptibility, whereas intermediate resistance to ciprofloxacin was negligible. Two strains were extended spectrum β-lactamase (ESBL) producers. Analysis of PFGE patterns uncovered a predominant cluster (similarity coefficient above 80%) consisting of 104 of the 153 strains. CONCLUSION: The worldwide increase of antibiotic resistances in Salmonella is an emerging public health problem. For Switzerland, no clear trend is identifiable over the years 2004 to 2009 for S. Virchow. Antimicrobial susceptibility and resistance profiles varied considerably within this period. Nevertheless, the situation in Switzerland coincided with findings in other European countries. Genotyping results of this strain collection revealed no evidence for an undetected outbreak within this time period

    Between-day reliability of electromechanical delay of selected neck muscles during performance of maximal isometric efforts

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    <p>Abstract</p> <p>Background</p> <p>The purpose of this study was to assess the between-day reliability of the electromechanical delay (EMD) of selected neck muscles during the performance of maximal isometric contractions in five different directions.</p> <p>Methods</p> <p>Twenty-one physically active males participated in two testing sessions separated by seven to eight days. Using a custom-made fixed frame dynamometer, cervical force and surface electromyography (EMG) were recorded bilaterally from the splenius capitis, upper trapezius and sternocleidomastoid muscles during the performance of efforts in extension, flexion, left and right lateral bending, and protraction. The EMD was extracted using the Teager-Kaiser Energy Operator. Reliability indices calculated for each muscle in each testing direction were: the difference in scores between the two testing sessions and corresponding 95% confidence intervals, the standard error of measurement (SEM) and intra-class correlation coefficients (ICC).</p> <p>Results</p> <p>EMD values showed no evidence of systematic difference between the two testing sessions across all muscles and testing directions. The SEM for extension, flexion and lateral bending efforts ranged between 2.5 ms to 4.8 ms, indicating a good level of measurement precision. For protraction, SEM values were higher and considered to be imprecise for research and clinical purposes. ICC values for all muscles across all testing directions ranged from 0.23 to 0.79.</p> <p>Conclusion</p> <p>EMD of selected neck muscles can be measured with sufficient precision for the assessment of neck muscle function in an athletic population in the majority of directions tested.</p
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