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1.
Science ; 372(6546): 1081-1085, 2021 06 04.
Article in English | MEDLINE | ID: mdl-34083487

ABSTRACT

Gamma-ray bursts (GRBs), which are bright flashes of gamma rays from extragalactic sources followed by fading afterglow emission, are associated with stellar core collapse events. We report the detection of very-high-energy (VHE) gamma rays from the afterglow of GRB 190829A, between 4 and 56 hours after the trigger, using the High Energy Stereoscopic System (H.E.S.S.). The low luminosity and redshift of GRB 190829A reduce both internal and external absorption, allowing determination of its intrinsic energy spectrum. Between energies of 0.18 and 3.3 tera-electron volts, this spectrum is described by a power law with photon index of 2.07 ± 0.09, similar to the x-ray spectrum. The x-ray and VHE gamma-ray light curves also show similar decay profiles. These similar characteristics in the x-ray and gamma-ray bands challenge GRB afterglow emission scenarios.

2.
Clin Biomech (Bristol, Avon) ; 71: 146-151, 2020 01.
Article in English | MEDLINE | ID: mdl-31743885

ABSTRACT

BACKGROUND: Many researchers emphasize adaptations following pregnancy. Our purpose was to get more insight into how morphology interacts with the pelvic walking pattern - the segment most prone to the adaptation following altered body demands. METHODS: Thirty women were enrolled. Three experimental sessions were arranged according to the same protocol in the first, second and third trimesters of pregnancy. First, the anthropometric measures were taken, then walking trials at a self-selected speed were registered. At the end of the experimental session the subjects were asked to fill out a questionnaire on pain. FINDINGS: The sagittal plane pelvic range of motion (RoM) significantly increased throughout pregnancy. There were significant positive correlations between pelvic anthropometric dimensions and pelvic tilt and rotation primarily in the third trimester of pregnancy. Significant positive correlations were found between pelvic RoM and thigh circumference. Indicators associated with body mass increase were positively correlated with pelvic obliquity in the second trimester and pelvic tilt and rotation in late pregnancy. It is also worth noting that the individual differences were not related to back pain and that the reported correlations were observed in some but not in all trimesters. INTERPRETATION: Morphological changes following the fetus growth induced increased pelvic tilt and rotation, however, pelvis movements were not associated with back pain. Overall, the results highlight correlations between morphology and pelvis kinematic patterns in some but not in all trimesters.


Subject(s)
Pelvis/diagnostic imaging , Pelvis/physiopathology , Posture , Pregnancy , Walking/physiology , Adaptation, Physiological , Adult , Anthropometry , Back Pain , Biomechanical Phenomena , Female , Gait , Humans , Movement , Pain Measurement , Range of Motion, Articular , Rotation , Young Adult
3.
Nature ; 575(7783): 464-467, 2019 11.
Article in English | MEDLINE | ID: mdl-31748724

ABSTRACT

Gamma-ray bursts (GRBs) are brief flashes of γ-rays and are considered to be the most energetic explosive phenomena in the Universe1. The emission from GRBs comprises a short (typically tens of seconds) and bright prompt emission, followed by a much longer afterglow phase. During the afterglow phase, the shocked outflow-produced by the interaction between the ejected matter and the circumburst medium-slows down, and a gradual decrease in brightness is observed2. GRBs typically emit most of their energy via γ-rays with energies in the kiloelectronvolt-to-megaelectronvolt range, but a few photons with energies of tens of gigaelectronvolts have been detected by space-based instruments3. However, the origins of such high-energy (above one gigaelectronvolt) photons and the presence of very-high-energy (more than 100 gigaelectronvolts) emission have remained elusive4. Here we report observations of very-high-energy emission in the bright GRB 180720B deep in the GRB afterglow-ten hours after the end of the prompt emission phase, when the X-ray flux had already decayed by four orders of magnitude. Two possible explanations exist for the observed radiation: inverse Compton emission and synchrotron emission of ultrarelativistic electrons. Our observations show that the energy fluxes in the X-ray and γ-ray range and their photon indices remain comparable to each other throughout the afterglow. This discovery places distinct constraints on the GRB environment for both emission mechanisms, with the inverse Compton explanation alleviating the particle energy requirements for the emission observed at late times. The late timing of this detection has consequences for the future observations of GRBs at the highest energies.

4.
Gait Posture ; 68: 518-524, 2019 02.
Article in English | MEDLINE | ID: mdl-30623846

ABSTRACT

BACKGROUND: Progressive weight gain and changes in its distribution following pregnancy may be challenging for the gravidas' ability to move in a stable way. RESEARCH QUESTION: How is gait kinematics changing throughout pregnancy and to what extend is it affected by physical activity level and energy balance? METHODS: 30 women were enrolled. Three experimental sessions were arranged according to the same protocol in the first, second and third trimesters of pregnancy. Walking kinematics at a self-selected speed was registered. The total physical activity (TPA) was assessed from the subjects' questionnaires. Energy balance ('positive', 'balanced' or 'negative') was estimated as the difference between dietary energy intake and energy expenditure during 7 days. RESULTS: No significant differences were found in the spatiotemporal variables between experimental sessions. However, the gait analysis revealed significant increments in the single support and base of support (BoS) measures. Generally, the sagittal plane mobility of the lower limb joints did not differ, however, the pelvic tilt increased in late pregnancy. The hip and pelvis angles were significantly different over the gait cycle throughout gestation. The 'balanced' energy was dominant in the first trimester although the relative number of participants with negative balance increased over pregnancy. Overall, gait parameters were independent of the energy balance. However, significant correlation was found between gait parameters, such as BoS, velocity, stride length, and TPA in the advanced pregnancy. SIGNIFICANCE: The longitudinal assessment of walking kinematics demonstrates few changes adopted to accommodate for pregnancy. The enlargement of BoS is considered as a strategy to provide safety and stability. The increased pelvic tilt is likely to compensate for changes in the body mass distribution. The physical activity correlates with the BoS measures and stride length and thus may be important for enhancing gait stability.


Subject(s)
Exercise/physiology , Gait/physiology , Lower Extremity/physiology , Posture/physiology , Range of Motion, Articular/physiology , Walking/physiology , Adult , Biomechanical Phenomena , Female , Follow-Up Studies , Humans , Pregnancy , Pregnancy Trimester, Third , Time Factors , Young Adult
5.
Neurol Neurochir Pol ; 33(4): 935-42, 1999.
Article in Polish | MEDLINE | ID: mdl-10612107

ABSTRACT

Borreliosis is a systemic disease proceeding chronically, in stages and with dermatological, rheumatological and cardiological manifestations. In international terminology the name Lyme borreliosis is most commonly used. Recently the number of the incidents of this disease has increased in Poland as well, particularly among those employed in forests located in endemic regions, which has been confirmed in publications. In this article we present an unusual case of the coexistence of Borrelia burgdorferi infection with cervical medulla injury resulting from discopathy observed in a 65-year-old patient, who additionally suffered from arterial hypertension and diabetes.


Subject(s)
Intervertebral Disc Displacement/complications , Lyme Disease/diagnosis , Spinal Cord Injuries/etiology , Aged , Borrelia burgdorferi Group/isolation & purification , Female , Humans , Lyme Disease/complications , Lyme Disease/microbiology
6.
Neurol Neurochir Pol ; 32(2): 401-7, 1998.
Article in Polish | MEDLINE | ID: mdl-9760559

ABSTRACT

This paper presents a case of multifocal metastases in the brain, which on the basis of typical imaging magnetic resonance and computerized tomography suggested possible parasitic changes (cerebral cysticercosis). On the basis of these pictures cerebral cysticercosis was diagnosed, in spite in the absence of serologic changes in blood and cerebrospinal fluid. The lack of improvement after anticysticercosis drugs, the further course of the disease as well as new foci located in other organs outside the brain, allowed to recognize numerous metastases in the brain although until the end of the clinical observation the primary lesion of the neoplasm was not found. The histopathological examination of samples of brain tissue confirmed the diagnosis of numerous metastases of poorly differentiated carcinoma.


Subject(s)
Brain Neoplasms/diagnosis , Carcinoma/diagnosis , Brain Neoplasms/surgery , Carcinoma/surgery , Cysticercosis/diagnosis , Cysticercosis/parasitology , Diagnostic Errors , Fatal Outcome , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Neoplasms, Multiple Primary/diagnosis , Tomography, X-Ray Computed
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