1,389 research outputs found

    Fermi-LAT upper limits on gamma-ray emission from colliding wind binaries

    Full text link
    Context: Colliding wind binaries (CWBs) are thought to give rise to a plethora of physical processes including acceleration and interaction of relativistic particles. Observation of synchrotron radiation in the radio band confirms there is a relativistic electron population in CWBs. Accordingly, CWBs have been suspected sources of high-energy gamma-ray emission since the COS-B era. Theoretical models exist that characterize the underlying physical processes leading to particle acceleration and quantitatively predict the non-thermal energy emission observable at Earth. Aims: We strive to find evidence of gamma-ray emission from a sample of seven CWB systems: WR 11, WR 70, WR 125, WR 137, WR 140, WR 146, and WR 147. Theoretical modelling identified these systems as the most favourable candidates for emitting gamma-rays. We make a comparison with existing gamma-ray flux predictions and investigate possible constraints. Methods: We used 24 months of data from the Large Area Telescope (LAT) on-board the Fermi Gamma Ray Space Telescope to perform a dedicated likelihood analysis of CWBs in the LAT energy range. Results: We find no evidence of gamma-ray emission from any of the studied CWB systems and determine corresponding flux upper limits. For some CWBs the interplay of orbital and stellar parameters renders the Fermi-LAT data not sensitive enough to constrain the parameter space of the emission models. In the cases of WR140 and WR147, the Fermi-LAT upper limits appear to rule out some model predictions entirely and constrain theoretical models over a significant parameter space. A comparison of our findings to the CWB eta Car is made.Comment: 9 pages, 3 figure

    Increased neutrophil-lymphocyte ratio in delirium

    Get PDF
    Aim: Delirium is a common and severe complication among older hospitalized patients. The pathophysiology is poorly understood, but it has been suggested that inflammation and oxidative stress may play a role. The aim of this pilot study was to investigate levels of the neutrophil-lymphocyte ratio (NLR) - a marker of systemic inflammation and oxidative stress - in patients with and without delirium. Methods: This pilot study was performed within a retrospective chart review study that included acutely ill patients, 65 years and older, who were admitted to the ward of geriatrics of the Erasmus University Medical Center. All patients in whom the differential white blood cell (WBC) counts as well as the C-reactive protein (CRP) level were determined within 24 h after admission were included in the present study. Differences in NLR between patients with and without delirium were investigated using univariate analysis of variance, with adjustments for age, sex, comorbidities, CRP level, and total WBC count. Results: Eighty-six patients were included. Thirteen patients were diagnosed with delirium. In adjusted models, higher mean NLR values were found in patients with, than in those without, delirium (9.10 vs 5.18, P=0.003). Conclusion: In this pilot study, we found increased NLR levels in patients with delirium. This finding might suggest that an inadequate response of the immune system and oxidative stress may play a role in the pathogenesis of delirium. Further studies are needed to confirm the association between NLR and delirium

    Сучасний стан пенсійного забезпечення в Україні

    Get PDF
    У статті розглянуто сучасний стан солідарної системи загальнообов'язкового державного пенсійного страхування та проаналізовано основні показники функціонування недержавних пенсійних фондів.In the article the current state of solidarity system of obligatory slate pension insurance is considered. The basic indicators of functioning of non-stale pension funds are analyzed

    Delirium in Old Age : Pathophysiological and Pharmacological Aspects

    Get PDF
    Delirium, an acute neuropsychiatric syndrome, affects approximately 1 out of 3 older patients admitted to the hospital and is associated with poor outcomes, including increased rates of postdischarge institutionalization, cognitive decline and mortality. Approximately 20 to 25% of the patients who experience delirium dies within 6 to 12 months. Despite the high prevalence and clinical impact, very little is known about the underlying pathogenesis. In this thesis, we have investigated potential novel biomarkers of delirium and the role of pharmacological agents in the development of delirium. The findings may contribute to a better understanding of the pathophysiology and may help to improve the prediction, detection and treatment of this syndrome

    Pleistocene landscape evolution in the Avon valley, southern Britain: optical dating of terrace formation and Palaeolithic archaeology

    Get PDF
    This paper presents the first comprehensive Optically Stimulated Luminescence dating programme from a sequence of Pleistocene river terraces in the Avon valley (Wiltshire-Hampshire-Dorset), southern Britain. These results offer the most complete chronometric framework for Pleistocene landscape evolution and Palaeolithic occupation in the Avon valley, allowing for the first time: (1) an assessment of the timing of terrace formation and landscape evolution, (2) the dating of hominin presence in the area, and (3) an investigation of the relationship between terrace formation and Quaternary climatic change. Analysis of 25 samples collected from terraces 10 and 7 to 4 show that the middle Avon terraces formed in response to the main Pleistocene climatic oscillations (Marine Isotope Stage (MIS) 10, 8, 6) and that fluvial mechanisms changed through time, resulting in three different types of terrace architecture. The highest and oldest deposits are compound terraces deposited during the Early Pleistocene before the Mid Pleistocene Transition. The middle reach of the valley is characterised by well-developed strath terraces overlain with thick fluvial deposits, reflecting the greater degree of incision in response to the increased amplitude of climate cycles in the Middle Pleistocene. The youngest deposits in the confined modern floodplain represent cut-and-fill terraces deposited after MIS5e. The results indicate that the two main Palaeolithic sites in the area, Milford Hill and Woodgreen, date to between at least MIS 10 and 8 with a pre-MIS 10 human occupation at a third main site at Bemerton. This is significant because the sites date to a period previously associated with a decline in hominin presence in Britain. The dating of the Avon valley terrace sequence highlights the complex nature of terrace formation during the Pleistocene and the need to critically reassess the chronological understanding of these fluvial archives in southern Britain. This research demonstrates that with a detailed and multidisciplinary approach shifts in hominin landscape use can be discovered, providing new information on hominin behavioural change during the Pleistocene

    Triggering Mechanisms for Motor Actions: The Effects of Expectation on Reaction Times to Intense Acoustic Stimuli

    Get PDF
    Motor actions can be released much sooner than normal when the go-signal is of very high intensity (>100 dBa). Although statistical evidence from individual studies has been mixed, it has been assumed that sternocleidomastoid (SCM) muscle activity could be used to distinguish between two neural circuits involved in movement triggering. We summarized meta-analytically the available evidence for this hypothesis, comparing the difference in premotor reaction time (RT) of actions where SCM activity was elicited (SCM+ trials) by loud acoustic stimuli against trials in which it was absent (SCM- trials). We found ten studies, all reporting comparisons between SCM+ and SCM- trials. Our mini meta-analysis showed that premotor RTs are faster in SCM+ than in SCM- trials, but the effect can be confounded by the variability of the foreperiods employed. We present experimental data showing that foreperiod predictability can induce differences in RT that would be of similar size to those attributed to the activation of different neurophysiological pathways to trigger prepared actions. We discuss plausible physiological mechanisms that would explain differences in premotor RTs between SCM+ and SCM- trials

    Assessment of anti-inflammatory tumor treatment efficacy by longitudinal monitoring employing sonographic micro morphology in a preclinical mouse model

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>With the development of increasingly sophisticated three-dimensional volumetric imaging methods, tumor volume can serve as a robust and reproducible measurement of drug efficacy. Since the use of molecularly targeted agents in the clinic will almost certainly involve combinations with other therapeutic modalities, the use of volumetric determination can help to identify a dosing schedule of sequential combinations of cytostatic drugs resulting in long term control of tumor growth with minimal toxicity. The aim of this study is to assess high resolution sonography imaging for the in vivo monitoring of efficacy of Infliximab in pancreatic tumor.</p> <p>Methods</p> <p>In the first experiment, primary orthotopic pancreatic tumor growth was measured with Infliximab treatment. In the second experiment, orthotopic tumors were resected ten days after inoculation of tumor cells and tumor recurrence was measured following Infliximab treatment. Tumor progression was evaluated using 3D high resolution sonography.</p> <p>Results</p> <p>Sonography measurement of tumor volume in vivo showed inhibitory effect of Infliximab on primary tumor growth in both non-resected and resected models. Measurement of the dynamics of tumor growth by sonography revealed that in the primary tumor Infliximab is effective against established tumors while in the resection model, Infliximab is more effective at an early stage following tumor resection. Infliximab treatment is also effective in inhibiting tumor growth growth as a result of tumor cell contamination of the surgical field.</p> <p>Conclusions</p> <p>Clinical application of Infliximab is feasible in both the neoadjuvant and adjuvant setting. Infliximab is also effective in slowing the growth of tumor growth under the peritoneum and may have application in treating peritoneal carcinomatosis. Finally the study demonstrates that high resolution sonography is a sensitive imaging modality for the measurement of pancreatic tumor growth.</p

    Multiscale heterogeneity in gastric adenocarcinoma evolution is an obstacle to precision medicine

    Get PDF
    Cancer is a somatic evolutionary disease and adenocarcinomas of the stomach and gastroesophageal junction (GC) may serve as a two-dimensional model of cancer expansion, in which tumor subclones are not evenly mixed during tumor progression but rather spatially separated and diversified. We hypothesize that precision medicine efforts are compromised when clinical decisions are based on a single-sample analysis, which ignores the mechanisms of cancer evolution and resulting intratumoral heterogeneity. Using multiregional whole-exome sequencing, we investigated the effect of somatic evolution on intratumoral heterogeneity aiming to shed light on the evolutionary biology of GC

    Ю.О. Митропольський — вчений та вихователь молоді

    Get PDF
    Висвітлено наукову діяльність та роботу з підготовки наукових кадрів академіка Ю.О. Митропольського. Змальовано його риси як вченого та вихователя молоді.Освещены научная деятельность и работа по подготовке научных кадров академика Ю.А.Митропольского. Обрисованы его черты как ученого и воспитателя молодежи.The paper highlights research and tutorial activities by Academician Yu.O. Mitropolsky. His qualities as a scientist and a tutor of youth are outlined
    corecore