20 research outputs found

    Heavy element production in a compact object merger observed by JWST

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    The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs) 1, sources of high-frequency gravitational waves (GWs) 2 and likely production sites for heavy-element nucleosynthesis by means of rapid neutron capture (the r-process) 3. Here we present observations of the exceptionally bright GRB 230307A. We show that GRB 230307A belongs to the class of long-duration GRBs associated with compact object mergers 4–6 and contains a kilonova similar to AT2017gfo, associated with the GW merger GW170817 (refs. 7–12). We obtained James Webb Space Telescope (JWST) mid-infrared imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns, which we interpret as tellurium (atomic mass A = 130) and a very red source, emitting most of its light in the mid-infrared owing to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can create r-process elements across a broad atomic mass range and play a central role in heavy-element nucleosynthesis across the Universe

    31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

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    Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival

    Acquiring Manual Flying Skills in a Virtual Reality Flight Simulator

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    In this study, we explored the possibility of objectively assessing the progress in manual flying skills by student pilots using Virtual Reality (VR). Using a VR flight simulator of the Pilatus PC-7 training aircraft, fifteen participants without flying experience practiced basic flight maneuvers based on self-study and without receiving feedback. Relevant flight performance measures were normalized and a learning curve was fitted, representing learning speed and end-level. During some runs an N-back task was included as a secondary task to quantify the participants’ cognitive capacity. Interestingly, performance on the N-back was not a good predictor of someone’s learning curve. The correlation between performance measures and flight instructor gradings confirmed that, for a limited set of maneuvers, we were able to objectify the students’ learning behavior of acquiring a set of manual flying skills in a VR flight simulator. The results of this study show the potential of measuring learning performance in VR

    Measuring the Lookout Behavior of Student Pilots in a Virtual Reality Flight Simulator

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    Learning adequate gaze behavior is essential in flight training. In this exploratory study we investigated the development of gaze behavior in flight training in a virtual reality (VR) flight simulator. Following standardized study material, fifteen participants without flying experience repeatedly practiced three basic flight maneuvers in a VR simulator of a small aircraft. During some runs, participants performed an additional N-back task to measure cognitive spare capacity. From the recorded gaze data we computed the percentage of time during which the gaze was directed outside the cockpit, i.e., the “Lookout”. This outside dwell ratio differed between flight maneuvers. A higher outside dwell ratio was associated with better flight performance. Remarkably, the outside dwell ratio increased with the additional N-back task. A heatmap indicated staring behavior during the N-back. In a follow-up study we will extend the analysis of gaze behavior with more dynamic measures than only the dwell ratio

    Clinical characteristics associated with pain in patients with peripheral vascular malformations

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    Objective: Vascular malformations (VM) can negatively impact the patient's quality of life (QoL). Pain is a common problem in these patients. The aim of this study was to investigate risk factors associated with pain and to assess how pain affects QoL. Methods: This prospective cross-sectional study was conducted in a tertiary vascular anomaly expertise center. Between June and December 2020, all patients from our local database (334 adults and 189 children) with peripheral VMs were invited to complete the Outcome Measures for VAscular MAlformations questionnaire to evaluate the presence, frequency, and intensity of pain. Additionally, patients were asked to complete several Patient-Reported Outcome Measurement Information System scales to evaluate their QoL. Risk factors associated with pain were identified in bivariate analysis and multivariable logistic regression. QoL domains were compared between patients who experienced pain and patients who did not. Results: A total of 164 patients completed the questionnaire about pain and 133 patients completed all QoL questionnaires. Approximately one-half of the patients (52%) reported pain in the past four weeks and 57% of these patients reported pain daily or several times a week. Female sex (P = .009), lesions located in the upper extremity (P < .001) or lower extremity (P < .001), and intramuscular/intraosseous lesions (P = .004) were independently associated with the presence of pain. The following QoL domains were diminished in patients who experienced pain in comparison with patients who did not: pain interference (P < .001), physical functioning (P < .001), and social participation (P < .001) in adults, and pain interference (P = .001), mobility (P = .001), and anxiety (P = .024) in children. Conclusions: Pain is a frequently reported complaint in patients with VMs and is present in approximately one-half of the patients. Patients with lesions located in the upper or lower extremity, intramuscular/intraosseous lesions, and female patients are more likely to experience pain. The presence of pain negatively impacted patients' QoL. Although VM are a benign condition and expectative management is frequently applied, our study shows that pain is a serious concern and needs to be actively assessed. Pain is a sign of various etiologies and should be examined to properly treat the pain

    JWST detection of heavy neutron capture elements in a compact object merger

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    The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs), sources of high-frequency gravitational waves and likely production sites for heavy element nucleosynthesis via rapid neutron capture (the r-process). These heavy elements include some of great geophysical, biological and cultural importance, such as thorium, iodine, and gold. Here we present observations of the exceptionally bright gamma-ray burst GRB230307A. We show that GRB 230307A belongs to the class of long-duration gamma-ray bursts associated with compact object mergers, and contains a kilonova similar to AT2017gfo, associated with the gravitational-wave merger GW170817. We obtained James Webb Space Telescope mid-infrared (mid-IR) imaging and spectroscopy 29 &amp; 61 days after the burst. The spectroscopy shows an emission line at 2.1 microns which we interpret as tellurium (atomic mass A=130), and a very red source, emitting most of its light in the mid-IR due to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can create r-process elements across a broad atomic mass range and play a central role in heavy element nucleosynthesis across the Universe

    Heavy element production in a compact object merger observed by JWST

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    The mergers of binary compact objects such as neutron stars and black holes are of central interest to several areas of astrophysics, including as the progenitors of gamma-ray bursts (GRBs) , sources of high-frequency gravitational waves (GW) and likely production sites for heavy element nucleosynthesis via rapid neutron capture (the r-process) . Here we present observations of the exceptionally bright gamma-ray burst GRB 230307A. We show that GRB 230307A belongs to the class of long-duration gamma-ray bursts associated with compact object mergers , and contains a kilonova similar to AT2017gfo, associated with the gravitational-wave merger GW170817 . We obtained James Webb Space Telescope mid-infrared (mid-IR) imaging and spectroscopy 29 and 61 days after the burst. The spectroscopy shows an emission line at 2.15 microns which we interpret as tellurium (atomic mass A=130), and a very red source, emitting most of its light in the mid-IR due to the production of lanthanides. These observations demonstrate that nucleosynthesis in GRBs can create r-process elements across a broad atomic mass range and play a central role in heavy element nucleosynthesis across the Universe. [Abstract copyright: © 2023. The Author(s), under exclusive licence to Springer Nature Limited.
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