| 1. |
- Algaba, Juan-Carlos, et al.
(författare)
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Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
- 2021
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 911:1
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Forskningsöversikt (refereegranskat)abstract
- In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M o˙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded.
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| 2. |
- Weinstock, Joshua S, et al.
(författare)
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Aberrant activation of TCL1A promotes stem cell expansion in clonal haematopoiesis.
- 2023
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Ingår i: Nature. - 1476-4687. ; 616:7958, s. 755-763
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Tidskriftsartikel (refereegranskat)abstract
- Mutations in a diverse set of driver genes increase the fitness of haematopoietic stem cells (HSCs), leading to clonal haematopoiesis1. These lesions are precursors for blood cancers2-6, but the basis of their fitness advantage remains largely unknown, partly owing to a paucity of large cohorts in which the clonal expansion rate has been assessed by longitudinal sampling. Here, to circumvent this limitation, we developed a method to infer the expansion rate from data from a single time point. We applied this method to 5,071 people with clonal haematopoiesis. A genome-wide association study revealed that a common inherited polymorphism in the TCL1A promoter was associated with a slower expansion rate in clonal haematopoiesis overall, but the effect varied by driver gene. Those carrying this protective allele exhibited markedly reduced growth rates or prevalence of clones with driver mutations in TET2, ASXL1, SF3B1 and SRSF2, butthis effect was not seen inclones withdriver mutations in DNMT3A. TCL1A was not expressed in normal or DNMT3A-mutated HSCs, but the introduction of mutations in TET2 or ASXL1 led to the expression of TCL1A protein and the expansion of HSCs in vitro. The protective allele restricted TCL1A expression and expansion of mutant HSCs, as did experimentalknockdown of TCL1A expression. Forced expression of TCL1A promoted the expansion of human HSCs in vitro and mouse HSCs in vivo. Our results indicate that the fitness advantage of several commonly mutated driver genes in clonal haematopoiesis may be mediated by TCL1A activation.
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| 3. |
- Vinterstare, Jerker, et al.
(författare)
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More than meets the eye : Predator-induced pupil size plasticity in a teleost fish
- 2020
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Ingår i: Journal of Animal Ecology. - : Wiley-Blackwell. - 0021-8790 .- 1365-2656. ; 89:10, s. 2258-2267
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Tidskriftsartikel (refereegranskat)abstract
- Most animals are visually oriented, and their eyes provide their ‘window to the world’. Eye size correlates positively with visual performance, because larger eyes can house larger pupils that increase photon catch and contrast discrimination, particularly under dim light, which have positive effects on behaviours that enhance fitness, including predator avoidance and foraging. Recent studies have linked predation risk to selection for larger eyes and pupils, and such changes should be of importance for the majority of teleost fishes as they have a pupil that is fixed in size (eyes lack a pupillary sphincter muscle) and, hence, do not respond to changes in light conditions. Here, we quantify eye and pupil size of individual crucian carp, a common freshwater fish, following controlled manipulations of perceived predation risk (presence/absence). We also tested if crucian carp responded to increased predation risk by shifts in diel activity patterns. We found that crucian carp show phenotypic plasticity with regards to pupil size, but not eye size, as pupil size increased when exposed to predators (pike). Predator-exposed crucian carp also shifted from diurnal to nocturnal activity. Using a modelling exercise, we moreover show that the plastically enlarged pupils significantly increase visual range, especially for small objects under dim light conditions. Overall, our results provide compelling evidence for predator-induced pupil enlargement resulting in enhanced visual capabilities in a teleost fish. Pupil size plasticity in combination with the observed shift towards nocturnal activity may allow for efficient foraging also under dark conditions when predation risk from diurnal and visually oriented predators is reduced. The data highlight the powerful role of predation risk for eye development and evolution.
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| 4. |
- Killander, F, et al.
(författare)
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No increased cardiac mortality or morbidity of radiotherapy in breast cancer patients after breast conserving surgery: 20 years follow-up of the randomised x trial.
- 2020
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Ingår i: International journal of radiation oncology, biology, physics. - : Elsevier BV. - 1879-355X .- 0360-3016. ; 107:4, s. 701-9
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Tidskriftsartikel (refereegranskat)abstract
- Radiotherapy (RT) after breast conserving surgery reduces loco-regional recurrences and improves survival, but may cause late side effects. The main purpose of this paper was to investigate long-term side effects after whole breast RT in a randomised clinical trial initiated in 1991 and to report dose-volume data based on individual 3D treatment plans for organs at risk (OR).The trial included 1187 T1-2 N0 breast cancer patients randomised to postoperative tangential whole breast radiotherapy or no further treatment. The prescription dose to the clinical target volume was 48-54 Gy. We present 20 year follow-up on survival, cause of death, morbidity and later malignancies. For a cohort of patients (n=157) with accessible CT-based 3D treatment plans in Dicom-RT format, dose-volume descriptors for OR were derived. In addition, these were compared with dose-volume data for a cohort of patients treated with contemporary RT techniques.The cumulative incidence of cardiac mortality was 12.4 % in the control group and 13.0 % in the RT group (P= 0.8). There was an increase in stroke mortality, 3.4 % in the control group versus 6.7 % in the RT group (P=0.018). Incidences of contra lateral breast cancer and lung cancer were similar between groups. The median Dmean (range) heart dose for left-sided treatments was 3.0 Gy (1.1-8.1) and the corresponding value for patients treated in 2017 was 1.5 Gy (0.4-6.0).In this trial serious late side effects of whole breast radiotherapy were limited and less than previously reported in large meta-analyses. We observed no increased cardiac mortality in irradiated patients with doses to the heart were median Dmean 3.0 Gy for left-sided RT. The observed increase in stroke mortality may partly be secondary to cardiac side effects, complications to anticoagulant treatment, or to chance, rather than a direct side effect of tangential whole breast irradiation.
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| 5. |
- Ljungholm, Mikael, et al.
(författare)
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Modelling the visual world of a velvet worm
- 2021
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Ingår i: PLoS Computational Biology. - : Public Library of Science (PLoS). - 1553-734X .- 1553-7358. ; 17:7
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Tidskriftsartikel (refereegranskat)abstract
- In many animal phyla, eyes are small and provide only low-resolution vision for general orientation in the environment. Because these primitive eyes rarely have a defined image plane, traditional visual-optics principles cannot be applied. To assess the functional capacity of such eyes we have developed modelling principles based on ray tracing in 3D reconstructions of eye morphology, where refraction on the way to the photoreceptors and absorption in the photopigment are calculated incrementally for ray bundles from all angles within the visual field. From the ray tracing, we calculate the complete angular acceptance function of each photoreceptor in the eye, revealing the visual acuity for all parts of the visual field. We then use this information to generate visual filters that can be applied to high resolution images or videos to convert them to accurate representations of the spatial information seen by the animal. The method is here applied to the 0.1 mm eyes of the velvet worm Euperipatoides rowelli (Onychophora). These eyes of these terrestrial invertebrates consist of a curved cornea covering an irregular but optically homogeneous lens directly joining a retina packed with photoreceptive rhabdoms. 3D reconstruction from histological sections revealed an asymmetric eye, where the retina is deeper in the forward-pointing direction. The calculated visual acuity also reveals performance differences across the visual field, with a maximum acuity of about 0.11 cycles/deg in the forward direction despite laterally pointing eyes. The results agree with previous behavioural measurements of visual acuity, and suggest that velvet worm vision is adequate for orientation and positioning within the habitat.
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| 6. |
- McGreevy, David, 1988-, et al.
(författare)
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Feasibility and Clinical Outcome of Reboa in Patients with Impending Traumatic Cardiac Arrest
- 2020
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Ingår i: Shock. - : Lippincott Williams & Wilkins. - 1073-2322 .- 1540-0514. ; 54:2, s. 218-223
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) may improve Systolic Blood Pressure (SBP) in hypovolemic shock. It has, however, not been studied in patients with impending traumatic cardiac arrest (ITCA). We aimed to study the feasibility and clinical outcome of REBOA in patients with ITCA using data from the ABOTrauma Registry.METHODS: Retrospective and prospective data on the use of REBOA from 16 centers globally were collected. SBP was measured both at pre- and post-REBOA inflation. Data collected included patients' demography, vascular access technique, number of attempts, catheter size, operator, zone and duration of occlusion, and clinical outcome.RESULTS: There were 74 patients in this high-risk patient group. REBOA was performed on all patients. A 7-10Fr catheter was used in 66.7%, 58.5% were placed on the first attempt, 52.1% through blind insertion and 93.2% inflated in Zone I, 64.8% for a period of 30 to 60 minutes, 82.1% by ER doctors, trauma surgeons or vascular surgeons. SBP significantly improved to 90 mmHg following the inflation of REBOA. 36.6% of the patients survived.CONCLUSIONS: Our study has shown that REBOA may be performed in patients with ITCA, SBP can be elevated and 36.6% of the patients survived if REBOA placement is successful.
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| 7. |
- Nilsson, Dan E., et al.
(författare)
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Cephalopod versus vertebrate eyes
- 2023
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Ingår i: Current Biology. - 0960-9822. ; 33:20, s. 1100-1105
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Tidskriftsartikel (refereegranskat)abstract
- Vertebrates and cephalopods are the two major animal groups that view the world through sophisticated camera-type eyes. There are of course exceptions: nautiloid cephalopods have more simply built pinhole eyes. Excellent camera type eyes are also found in other animals, such as some spider groups, a few snails, and certain marine worms, but the vast majority of large camera-type eyes belong to cephalopods and vertebrates. Vertebrates and cephalopods also devote major parts of their brains to the processing of visual information. Obviously, there are differences in eye performance among cephalopods and vertebrates, but there are no major subgroups where vision seems to have low priority. The similarity in eye geometry is striking, especially between fish and coleoid cephalopods, with a hemispherical retina centred around a spherical lens. Do these similarities mean that vertebrate and cephalopod eyes are equally good? Comparing the eyes of vertebrates and cephalopods reveals many fundamental differences with surprisingly small consequences for vision, but also one difference that means that cephalopods and vertebrates do not share the same visual world.
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| 8. |
- Nilsson, Dan E., et al.
(författare)
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Lens eyes in protists
- 2020
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Ingår i: Current Biology. - : Elsevier BV. - 0960-9822. ; 30:10, s. 458-459
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Tidskriftsartikel (refereegranskat)abstract
- Eyes are not unique to animals. As described by Nilsson and Marshall, prominent eyes, complete with retina and lens, have unexpectedly evolved in single cell dinoflagellates.
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| 9. |
- Nilsson, Dan E.
(författare)
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Michael Francis Land FRS, 1942-2020
- 2021
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Ingår i: The Journal of experimental biology. - : The Company of Biologists. - 1477-9145 .- 0022-0949. ; 224
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Tidskriftsartikel (refereegranskat)
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| 10. |
- Nilsson, Dan E., et al.
(författare)
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Quantifying biologically essential aspects of environmental light
- 2021
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Ingår i: Journal of the Royal Society, Interface. - : The Royal Society. - 1742-5662. ; 18:177
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Tidskriftsartikel (refereegranskat)abstract
- Quantifying and comparing light environments are crucial for interior lighting, architecture and visual ergonomics. Yet, current methods only catch a small subset of the parameters that constitute a light environment, and rarely account for the light that reaches the eye. Here, we describe a new method, the environmental light field (ELF) method, which quantifies all essential features that characterize a light environment, including important aspects that have previously been overlooked. The ELF method uses a calibrated digital image sensor with wide-angle optics to record the radiances that would reach the eyes of people in the environment. As a function of elevation angle, it quantifies the absolute photon flux, its spectral composition in red-green-blue resolution as well as its variation (contrast-span). Together these values provide a complete description of the factors that characterize a light environment. The ELF method thus offers a powerful and convenient tool for the assessment and comparison of light environments. We also present a graphic standard for easy comparison of light environments, and show that different natural and artificial environments have characteristic distributions of light.
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