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Galaxy clusters magnify background objects through strong gravitational lensing. Typical magnifications for lensed galaxies are factors of a few but can also be as high as tens or hundreds, stretching galaxies into giant arcs1,2. Individual stars can attain even higher magnifications given fortuitous alignment with the lensing cluster. Recently, several individual stars at redshifts between approximately 1 and 1.5 have been discovered, magnified by factors of thousands, temporarily boosted by microlensing3-6. Here we report observations of a more distant and persistent magnified star at a redshift of 6.2 ± 0.1, 900 million years after the Big Bang. This star is magnified by a factor of thousands by the foreground galaxy cluster lens WHL0137-08 (redshift 0.566), as estimated by four independent lens models. Unlike previous lensed stars, the magnification and observed brightness (AB magnitude, 27.2) have remained roughly constant over 3.5 years of imaging and follow-up. The delensed absolute UV magnitude, -10 ± 2, is consistent with a star of mass greater than 50 times the mass of the Sun. Confirmation and spectral classification are forthcoming from approved observations with the James Webb Space Telescope.
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The engineering challenge of rolling bearing condition monitoring has led to a large number of method developments over the past few years. Most commonly, vibration measurement data are used for fault diagnosis using machine learning algorithms. In current research, purely data-driven deep learning methods are becoming increasingly popular, aiming for accurate predictions of bearing faults without requiring bearing-specific domain knowledge. Opposing this trend in popularity, the present paper takes a more traditional approach, incorporating domain knowledge by evaluating a variety of feature engineering methods in combination with a random forest classifier. For a comprehensive feature engineering study, a total of 42 mathematical feature formulas are combined with the preprocessing methods of envelope analysis, empirical mode decomposition, wavelet transforms, and frequency band separations. While each single processing method and feature formula is known from the literature, the presented paper contributes to the body of knowledge by investigating novel series connections of processing methods and feature formulas. Using the CWRU bearing fault data for performance evaluation, feature calculation based on the processing method of frequency band separation leads to particularly high prediction accuracies, while at the same time being very efficient in terms of low computational effort. Additionally, in comparison with deep learning approaches, the proposed feature engineering method provides excellent accuracies and enables explainability.
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OBJECTIVE: This paper analyses helmet use before and after implementing Helmets for Kids, a school-based helmet distribution and road safety programme in Cambodia. METHODS: Nine intervention schools (with a total of 6721 students) and four control schools (with a total of 3031 students) were selected using purposive sampling to target schools where students were at high risk of road traffic injury. Eligible schools included those where at least 50% of students commute to school on bicycles or motorcycles, were located on a national road (high traffic density), had few or no street signs nearby, were located in an area with a history of crash injuries and were in a province where other Cambodia Helmet Vaccine Initiative activities occur. Programme's effectiveness at each school was measured through preintervention and postintervention roadside helmet observations of students as they arrived or left school. Research assistants conducted observations 1-2â weeks preintervention, 1-2â weeks postintervention, 10-12â weeks postintervention and at the end of the school year (3-4â months postintervention). RESULTS: In intervention schools, observed student helmet use increased from an average of 0.46% at 1-2â weeks preintervention to an average of 87.9% at 1-2â weeks postintervention, 83.5% at 10-12â weeks postintervention and 86.5% at 3-4â months postintervention, coinciding with the end of the school year. Increased helmet use was observed in children commuting on bicycle or motorcycle, which showed similar patterns of helmet use. Helmet use remained between 0.35% and 0.70% in control schools throughout the study period. CONCLUSIONS: School-based helmet use programmes that combine helmet provision and road safety education might increase helmet use among children.
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Accidentes de Tránsito/prevención & control , Ciclismo/lesiones , Traumatismos Craneocerebrales/prevención & control , Dispositivos de Protección de la Cabeza/estadística & datos numéricos , Servicios de Salud Escolar , Adolescente , Cambodia , Niño , Femenino , Humanos , Masculino , Motocicletas , Seguridad , Instituciones AcadémicasRESUMEN
BACKGROUND: Monoclonal antibodies represent one option for treatment of COVID-19 early after infection. Although large clinical trials have been successfully conducted, real world data are needed to obtain a realistic assessment of the assumed effect on hospitalization rates. METHODS: For this retrospective, observational study, clinical data were collected in 2021 from outpatients (402) as well as hospitalized patients (350) receiving monoclonal antibodies Bamlanivimab, Casirivimab/Imdevimab or Etesevimab/Bamlanivimab. These data were compared with data from a control group of patients not receiving antibodies because admission to the hospital was too late for this therapy. RESULTS: Both groups showed a comparable spectrum of risk factors. Due to the late hospitalization of control patients, a higher frequency of severe symptoms, such as fever, dyspnea, syncope and lower viral load, were observed. CRP and leukocytes counts were also higher in the untreated group. Most importantly, hospitalization time was significantly shorter and the number of deaths was also lower in the treated group. CONCLUSIONS: Apparently, the application of anti-SARS-CoV-2 antibodies reduced the work load of our hospital as shown by the shorter hospitalization time and lower number of COVID-19-related deaths.
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With their high persistence in the environment and their potential for long-range atmospheric transport, persistent, bioaccumulative, and toxic chemicals (PBTs) may be among the numerous anthropogenic threats to insect populations worldwide. The effects of PBTs on insects have been investigated in the laboratory, but topical field studies are scarce. A reason might be the multiple challenges faced by PBT-related field studies on wild insects. We studied two species of bumblebees (Bombus spp.) and of ants (Formica spp.) in two high-elevation locations in the Austrian and German Alps to tackle two of these challenges. First, PBTs occur in minuscule concentrations compared with other substances in the environment. Therefore, the practicability of body burden data from pooled individuals was tested. Second, fitness proxies like fecundity, which typically are endpoints for chemical toxicity, are difficult to quantify in the field. Hence, fluctuating asymmetry of bumblebee wings and ant heads was tested as an alternative endpoint. To exclude the possibility that fluctuating asymmetry was caused by genetic stressors, inbreeding levels were estimated using population-genetic markers, and their relationships to fluctuating asymmetry in the same individuals were assessed. We successfully quantified polychlorinated biphenyls and Hg as PBTs using the pooled samples and found PBT data from pooled individuals useful, in that significant correlations to fluctuating asymmetry were identified in bumblebees and ants. This finding confirmed the potential of fluctuating asymmetry to indicate PBT effects in wild insects. Inbreeding did not interfere with PBT links to fluctuating asymmetry in any instance. Our findings contribute to the development of a quantitative methodological framework for investigating the effects of persistent environmental chemicals on wild insects. Environ Toxicol Chem 2022;41:1215-1227. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Mercurio , Animales , Abejas , Bioacumulación , Ecotoxicología , Humanos , Insectos , Mercurio/toxicidadRESUMEN
BACKGROUND: A fracture of the acetabulum is an uncommon, but serious injury. Established outcome tools do not reflect the patient's perspective after fracture of the hip joint. Originally designed for post-arthroplasty patients, the Forgotten Joint Score (FJS) is a patient-reported outcome measurement (PROM) tool evaluating the disease-specific health-related quality of life (HR-QoL). AIM: To validate the FJS in patients after acetabular fracture. METHODS: In a prospective mono-centric cohort study, we evaluated 100 patients at mean 5.2 ± 3.6 years after a fracture of the acetabulum. The validation study followed the complete COSMIN checklist protocol. For calculation of convergent validity, we used the Tegner-Activity Scale, the Western Ontario and McMaster Universities Osteoarthritis Index, the EuroQol-5D, and a subjective rating of change as an anchor variable. RESULTS: We confirmed good internal consistency with a Cronbach's alpha of 0.95. With an intraclass correlation coefficient of 0.99 (95%CI: 0.97, 0.99), test-retest reliability of the FJS was excellent. Correlation coefficients between the questionnaires were moderate to high ranging from |0.56| to |0.83| (absolute value). No relevant floor or ceiling effects occurred. Standard error of measurement was 3.2 and smallest detectable change (SDC) was 8.8. Thus, changes greater than 8.8 points between two assessments denote a real change in FJS. CONCLUSION: The FJS is a valid and reliable tool for evaluation of patient-reported outcome in posttraumatic condition after acetabular fracture. The SDC indicating a real clinical improvement was 8.8 points in the FJS. We could confirm responsiveness of the FJS and found no relevant floor- or ceiling effects.
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During the epoch of reionization, neutral gas in the early Universe was ionized by hard ultraviolet radiation emitted by young stars in the first galaxies. To do so, ionizing ultraviolet photons must escape from the host galaxy. We present Hubble Space Telescope observations of the gravitationally lensed post-reionization galaxy PSZ1-ARC G311.6602-18.4624 (nicknamed the "Sunburst Arc"), revealing bright, multiply imaged ionizing photon escape from a compact star-forming region through a narrow channel in an optically thick gas. The gravitational lensing magnification shows how ionizing photons escape this galaxy, contributing to the reionization of the Universe. The multiple sight lines to the source probe absorption by intergalactic neutral hydrogen on a scale of less than a few hundred parsecs.
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We present measurements of the surface density of star formation, the star-forming clump luminosity function, and the clump size distribution function, for the lensed galaxy SGAS J111020.0+645950.8 at a redshift of z =2.481. The physical size scales that we probe, radii r = 30-50 pc, are considerably smaller scales than have yet been studied at these redshifts. The star formation surface density we find within these small clumps is consistent with surface densities measured previously for other lensed galaxies at similar redshift. Twenty-two percent of the rest-frame ultraviolet light in this lensed galaxy arises from small clumps, with r <100 pc. Within the range of overlap, the clump luminosity function measured for this lensed galaxy is remarkably similar to those of z â¼ 0 galaxies. In this galaxy, star-forming regions smaller than 100 pc-physical scales not usually resolved at these redshifts by current telescopes-are important locations of star formation in the distant universe. If this galaxy is representative, this may contradict the theoretical picture in which the critical size scale for star formation in the distant universe is of order 1 kiloparsec. Instead, our results suggest that current telescopes have not yet resolved the critical size scales of star-forming activity in galaxies over most of cosmic time.
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BACKGROUND: Female Sex Workers (FSWs) are considered to be at high risk for transmission of Sexually Transmitted Infections (STIs) and are defined as a priority of the national HIV/AIDS response in the Republic of Congo (RoC). However, no data are available regarding STIs in this group. This study aimed to determine the prevalences of HIV, syphilis and hepatitis B and C among FSWs in five cities in the country. METHODS: A cross-sectional study was conducted from November 2nd 2011 to May 15th 2012. Participants were recruited in Brazzaville, Pointe-Noire, Dolisie, Nkayi and Pokola using a respondent-driven sampling method. RESULTS: A total of 805 FSWs were recruited with an average age of 28.31 ± 9.15 years. The overall prevalences of HIV, syphilis, HBV and HCV were 7.50%, 2.20%, 4.20% and 0.70%, respectively. The age groups 35-39 (20.51% [0%-36.93%], p = 0.0057) and greater than 40 years (16.67% [0%-34.93%], P = 0.016) were positively associated with behaviors at high risk of HIV infection. For syphilis, the most infected age group was the one greater than 40 years, at 6.25% ([1.06% -72.37%] p = 0.04). Pointe-Noire was the most infected city for syphilis and HBV, with 5.15% (p = 0.0061) and 4.22% (pË0.001), respectively. No risk factors were associated with HCV infection. FSWs practicing in mobile prostitution sites had a significantly higher infection rate (2.1% [0%-11.09%] p = 0.04). CONCLUSION: This study shows that the prevalence of HIV and other STIs in FSWs is high. Therefore, a combination of individual and structural interventions could reduce the risk of an STI "reservoir" among this population.
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Motorcycle fatalities are increasing at an alarming rate in many South-East Asian countries, including Cambodia. Through brief face-to-face roadside interviews in Phnom Penh and four other Cambodian provinces, this article assesses Cambodian motorcyclists' attitudes, behaviours and beliefs related to motorcycle helmets. Out of 1016 motorcyclists interviewed, 50% were drivers, 40% were older passengers and 10% were child passengers. More drivers (50%) reported consistently wearing helmets, compared with older passengers (14%). Saving their life in the event of a crash was the impetus for drivers and older passengers to wear a helmet (96% and 98%, respectively). The top barriers to helmet use were: (1) 'depends on where I drive,' (2) 'I forget' and (3) 'inconvenient' or 'uncomfortable'. These descriptive findings were instrumental in shaping the Cambodian Helmet Vaccine Initiative passenger campaign to reduce the motorcycle-related injuries and fatalities to support the United Nations Decade of Action for Road Safety.