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Local and low-redshift (z < 3) galaxies are known to broadly follow a bimodal distribution: actively star-forming galaxies with relatively stable star-formation rates and passive systems. These two populations are connected by galaxies in relatively slow transition. By contrast, theory predicts that star formation was stochastic at early cosmic times and in low-mass systems1-4. These galaxies transitioned rapidly between starburst episodes and phases of suppressed star formation, potentially even causing temporary quiescence-so-called mini-quenching events5,6. However, the regime of star-formation burstiness is observationally highly unconstrained. Directly observing mini-quenched galaxies in the primordial Universe is therefore of utmost importance to constrain models of galaxy formation and transformation7,8. Early quenched galaxies have been identified out to redshift z < 5 (refs. 9-12) and these are all found to be massive (Mâ > 1010 Mâ) and relatively old. Here we report a (mini-)quenched galaxy at z = 7.3, when the Universe was only 700 Myr old. The JWST/NIRSpec spectrum is very blue (U-V = 0.16 ± 0.03 mag) but exhibits a Balmer break and no nebular emission lines. The galaxy experienced a short starburst followed by rapid quenching; its stellar mass (4-6 × 108 Mâ) falls in a range that is sensitive to various feedback mechanisms, which can result in perhaps only temporary quenching.
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Galáxias , Fatores de Tempo , Astros Celestes , Meio Ambiente Extraterreno/químicaRESUMO
Several theories have been proposed to describe the formation of black hole seeds in the early Universe and to explain the emergence of very massive black holes observed in the first thousand million years after the Big Bang1-3. Models consider different seeding and accretion scenarios4-7, which require the detection and characterization of black holes in the first few hundred million years after the Big Bang to be validated. Here we present an extensive analysis of the JWST-NIRSpec spectrum of GN-z11, an exceptionally luminous galaxy at z = 10.6, revealing the detection of the [NeIV]λ2423 and CII*λ1335 transitions (typical of active galactic nuclei), as well as semi-forbidden nebular lines tracing gas densities higher than 109 cm-3, typical of the broad line region of active galactic nuclei. These spectral features indicate that GN-z11 hosts an accreting black hole. The spectrum also reveals a deep and blueshifted CIVλ1549 absorption trough, tracing an outflow with velocity 800-1,000 km s-1, probably driven by the active galactic nucleus. Assuming local virial relations, we derive a black hole mass of log ( M BH / M â ) = 6.2 ± 0.3 , accreting at about five times the Eddington rate. These properties are consistent with both heavy seeds scenarios and scenarios considering intermediate and light seeds experiencing episodic super-Eddington phases. Our finding explains the high luminosity of GN-z11 and can also provide an explanation for its exceptionally high nitrogen abundance.
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The first observations of the James Webb Space Telescope (JWST) have revolutionized our understanding of the Universe by identifying galaxies at redshift z ≈ 13 (refs. 1-3). In addition, the discovery of many luminous galaxies at Cosmic Dawn (z > 10) has suggested that galaxies developed rapidly, in apparent tension with many standard models4-8. However, most of these galaxies lack spectroscopic confirmation, so their distances and properties are uncertain. Here we present JWST Advanced Deep Extragalactic Survey-Near-Infrared Spectrograph spectroscopic confirmation of two luminous galaxies at z = 14.32 - 0.20 + 0.08 and z = 13.90 ± 0.17. The spectra reveal ultraviolet continua with prominent Lyman-α breaks but no detected emission lines. This discovery proves that luminous galaxies were already in place 300 million years after the Big Bang and are more common than what was expected before JWST. The most distant of the two galaxies is unexpectedly luminous and is spatially resolved with a radius of 260 parsecs. Considering also the very steep ultraviolet slope of the second galaxy, we conclude that both are dominated by stellar continuum emission, showing that the excess of luminous galaxies in the early Universe cannot be entirely explained by accretion onto black holes. Galaxy formation models will need to address the existence of such large and luminous galaxies so early in cosmic history.
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Large dust reservoirs (up to approximately 108 Mâ) have been detected1-3 in galaxies out to redshift z ≃ 8, when the age of the Universe was only about 600 Myr. Generating substantial amounts of dust within such a short timescale has proven challenging for theories of dust formation4,5 and has prompted the revision of the modelling of potential sites of dust production6-8, such as the atmospheres of asymptotic giant branch stars in low-metallicity environments, supernova ejecta and the accelerated growth of grains in the interstellar medium. However, degeneracies between different evolutionary pathways remain when the total dust mass of galaxies is the only available observable. Here we report observations of the 2,175 Å dust attenuation feature, which is well known in the Milky Way and galaxies at z â² 3 (refs. 9-11), in the near-infrared spectra of galaxies up to z ≃ 7, corresponding to the first billion years of cosmic time. The relatively short timescale implied for the formation of carbonaceous grains giving rise to this feature12 suggests a rapid production process, possibly in Wolf-Rayet stars or supernova ejecta.
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BACKGROUND: 98% of people with surgical conditions living in low- and middle-income countries (LMICs) do not receive safe, timely and affordable surgical and anesthesia care. Research exploring barriers to receiving care has tended to be narrow in focus, often facility-based and ignoring the community beliefs, experiences and behaviours that will be an essential component of closing the gap in surgical care. Using qualitative methods, we captured diverse community perspectives in rural Ethiopia: exploring beliefs, perceptions, knowledge and experiences related to surgical conditions, with the overall aim of (re)constructing explanatory models. METHODS: Our study was nested within a community-based survey of surgical conditions conducted in the Butajira Health and Demographic Surveillance Site, southern Ethiopia, and a follow-up study of people accessing surgical care in two local hospitals. We carried out 24 semi-structured interviews. Participants were community members who needed but did/did not access surgical care, community-based healthcare workers and traditional bone-setters. Interviews were conducted in Amharic, audio-recorded, transcribed, and translated into English. We initially carried out thematic analysis and we recognized that emerging themes were aligned with Kleinman's explanatory models framework and decided to use this to guide the final stages of analysis. RESULTS: We found that community members primarily understood surgical conditions according to severity. We identified two categories: conditions you could live with and those which required urgent care, with the latter indicating a clear and direct path to surgical care whilst the former was associated with a longer, more complex and experimental pattern of help-seeking. Fear of surgery and poverty disrupted help-seeking, whilst community narratives based on individual experiences fed into the body of knowledge people used to inform decisions about care. CONCLUSIONS: We found explanatory models to be flexible, responsive to new evidence about what might work best in the context of limited community resources. Our findings have important implications for future research and policy, suggesting that community-level barriers have the potential to be responsive to carefully designed interventions which take account of local knowledge and beliefs.
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Emergências , Acessibilidade aos Serviços de Saúde , Humanos , Pesquisa Qualitativa , Etiópia/epidemiologia , Seguimentos , População RuralRESUMO
BACKGROUND: The post-partum consumption of the placenta by the mother (placentophagy) has been practiced since the 1970s in the global North and is seemingly increasing in popularity. Maternal placentophagy is not known to have been practiced in any other time period or culture, despite being near-ubiquitous in other placental mammals. An in-depth qualitative exploration as to the reasons for the practice, its increasing popularity and how it is narratively incorporated into discourses surrounding "ideal" natural and medical births are given in this paper. METHODS: 1752 posts from 956 users across 85 threads from the parenting forums Mumsnet and Netmums were identified for inclusion. A thematic discourse analysis was performed using NVivo. RESULTS: Three main themes were identified: women recounted predominantly positive attitudes towards their own experiences of placentophagy, and they were respectful of others' views and experiences; some had negative views, particularly around the concept of disgust, but again, they were respectful of others' experiences. By far the most common method of consumption of the placenta was encapsulation. CONCLUSIONS: This paper identifies the motivation for placentophagy to almost universally be for medical benefits, most commonly the prevention or treatment of post-natal depression (PND). Whilst disgust is a common reaction, discussion of risks is rare, and positive experiences outweigh negative ones. The increasing popularity of the practice is ascribed in part to the comparative palatability of encapsulation and the use of the internet to share resources and remove barriers. Parenting forums are important spaces to negotiate normative birth practices, including placentophagy, and act to build communities of women who value personal experience over medical evidence and highly value personal choice and bodily autonomy. Placentophagy is discussed in terms of its relation to natural and medical births with arguments being made using both discourses for and against the practice. This paper argues that placentophagy is practiced as a resistance to medicalisation as an assertion of control by the mother, whilst simultaneously being a medicalised phenomenon itself.
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Ingestão de Alimentos , Conhecimentos, Atitudes e Prática em Saúde , Mães/psicologia , Parto , Placenta , Período Pós-Parto , Depressão Pós-Parto/prevenção & controle , Feminino , Humanos , Motivação , Gravidez , Reino UnidoRESUMO
BACKGROUND: Most international electives in which medical students from high-income countries travel abroad are largely unstructured, and can lead to problematic outcomes for students as well as sending and receiving institutions. We analyse the problems of unstructured medical electives and describe the benefits of an elective experience that includes more organisation and oversight from the sending medical school. RESULTS: A number of structured elective programmes have been developed, including those at the Medical School for International Health, Israel and the University of Dundee, United Kingdom. These programmes provide significant pre-departure training in global health and the ethical dimensions of electives, support and monitoring during the elective, and post-elective debrief. Crucially, the programmes themselves are developed on the basis of long-term engagement between institutions, and have an element of reciprocity. We further identify two major problems in current medical electives: the different ethical contexts in which electives take place, and the problem of 'voluntourism', in which the primary beneficiary of the activity is the medical student, rather than the receiving institution or health system. These two issues should be seen in the light of unequal relations between sending and receiving institutions, which largely mirror unequal relations between the Global North and South. CONCLUSION: We argue that more structured elective programmes could form a useful corrective to some of the problems identified with medical electives. We recommend that medical schools in countries such as the UK strongly consider developing these types of programmes, and if this is not possible, they should seek to further develop their pre-departure training curricula.
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Educação Médica/organização & administração , Intercâmbio Educacional Internacional , Faculdades de Medicina/organização & administração , Currículo , Humanos , Reino UnidoRESUMO
BACKGROUND: There is increasing interest in global health teaching among medical schools and their students. Schools in the UK and internationally are considering the best structure, methods and content of global health courses. Academic work in this area, however, has tended to either be normative (specifying what global health teaching ought to look like) or descriptive (of a particular intervention, new module, elective, etc.). METHODS: While a number of studies have explored student perspectives on global health teaching, these have often relied on tools such as questionnaires that generate little in-depth evidence. This study instead used qualitative methods to explore medical student perspectives on global health in the context of a new global health module established in the core medical curriculum at a UK medical school. RESULTS: Fifth year medical students participated in a structured focus group session and semi-structured interviews designed to explore their knowledge and learning about global health issues, as well as their wider perspectives on these issues and their relevance to professional development. While perspectives on global health ranged from global health 'advocate' to 'sceptic', all of the students acknowledged the challenges of prioritising global health within a busy curriculum. CONCLUSIONS: Students are highly alert to the diverse epistemological issues that underpin global health. For some students, such interdisciplinarity is fundamental to understanding contemporary health and healthcare. For others, global health is merely a topic of geographic relevance. Furthermore, some students appeared to accept global health as a specialist area only relevant to professionals working overseas, while others considered it to be an essential part of working in the globalised world and therefore relevant to all medical professionals. Students also clearly noted that including 'soft' subjects and more discursive approaches to teaching and learning often sits awkwardly in a programme where 'harder' forms of knowledge and didactic methods tend to dominate. This suggests that more work needs to be done to explain the relevance of global health to medical students at the very beginning of their studies.
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Atitude do Pessoal de Saúde , Educação de Graduação em Medicina/métodos , Saúde Global/educação , Estudantes de Medicina/psicologia , Currículo , Feminino , Grupos Focais , Humanos , Entrevistas como Assunto , Masculino , Pesquisa Qualitativa , Reino UnidoRESUMO
BACKGROUND: The health system of Iraqi Kurdistan is severely understudied, particularly with regard to patient-physician interactions and their effects. We examine patterns of behaviour among physicians in Kurdistan, the justifications given and possible enabling factors, with a view to understanding accountability both from above and below. METHODS: An ethnographic study was conducted in the Sulaimaniyah Teaching Hospital in the Kurdistan Region of Iraq. Data was collected through negotiated interactive observation, and interviews were conducted with 10 participants, 5 physicians and 5 patients. Data collected was analysed using thematic analysis. RESULTS: Common patterns of practice among physicians in Kurdistan include displays of discontent, reluctance to negotiate decisions with patients and unfavourable behaviours including dual practice and predatory behaviours towards patients. These behaviours are justified as a mechanism of dealing with negative aspects of their work, including overcrowding, low salaries and social pressure to live up to socially conceived ideas of a physician's identity. CONCLUSIONS: Michael Lipsky's theory of street-level bureaucrats and their coping behaviours is a useful way to analyse the Kurdish health system. Physician behaviours are enabled by a number of factors that work to enhance physician discretion through lowering of upward and downward accountability. Physicians are under very little pressure to change their behaviour, and as a result, they effectively become the street-level governing body of the Kurdish health system.
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Adaptação Psicológica , Atenção à Saúde , Satisfação no Emprego , Liderança , Relações Médico-Paciente , Médicos , Responsabilidade Social , Etnicidade , Humanos , IraqueRESUMO
BACKGROUND: There has long been debate around the definition of the field of education, research and practice known as global health. In this article we step back from attempts at definition and instead ask what current definitions tell us about the evolution of the field, identifying gaps and points of debate and using these to inform discussions of how global health might be taught. DISCUSSION: What we now know as global health has its roots in the late 19(th) century, in the largely colonial, biomedical pursuit of 'international health'. The twentieth century saw a change in emphasis of the field towards a much broader conceptualisation of global health, encompassing broader social determinants of health and a truly global focus. The disciplinary focus has broadened greatly to include economics, anthropology and political science, among others. There have been a number of attempts to define the new field of global health. We suggest there are three central areas of contention: what the object of knowledge of global health is, the types of knowledge to be used and around the purpose of knowledge in the field of global health. We draw a number of conclusions from this discussion. First, that definitions should pay attention to differences as well as commonalities in different parts of the world, and that the definitions of global health themselves depend to some extent on the position of the definer. Second, global health's core strength lies in its interdisciplinary character, in particular the incorporation of approaches from outside biomedicine. This approach recognises that political, social and economic factors are central causes of ill health. Last, we argue that definition should avoid inclusion of values. In particular we argue that equity, a key element of many definitions of global health, is a value-laden concept and carries with it significant ideological baggage. As such, its widespread inclusion in the definitions of global health is inappropriate as it suggests that only people sharing these values may be seen as 'doing' global health. Nevertheless, discussion of values should be a key part of global health education. SUMMARY: Our discussions lead us to emphasise the importance of an approach to teaching global health that is flexible, interdisciplinary and acknowledges the different interpretations and values of those practising and teaching the field.
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Educação de Graduação em Medicina , Saúde Global , Modelos Educacionais , Ensino , Currículo , HumanosRESUMO
BACKGROUND: Since the early 1990s there has been a burgeoning interest in global health teaching in undergraduate medical curricula. In this article we trace the evolution of this teaching and present recommendations for how the discipline might develop in future years. DISCUSSION: Undergraduate global health teaching has seen a marked growth over the past ten years, partly as a response to student demand and partly due to increasing globalization, cross-border movement of pathogens and international migration of health care workers. This teaching has many different strands and types in terms of topic focus, disciplinary background, the point in medical studies in which it is taught and whether it is compulsory or optional. We carried out a survey of medical schools across the world in an effort to analyse their teaching of global health. Results indicate that this teaching is rising in prominence, particularly through global health elective/exchange programmes and increasing teaching of subjects such as globalization and health and international comparison of health systems. Our findings indicate that global health teaching is moving away from its previous focus on tropical medicine towards issues of more global relevance. We suggest that there are three types of doctor who may wish to work in global health - the 'globalised doctor', 'humanitarian doctor' and 'policy doctor' - and that each of these three types will require different teaching in order to meet the required competencies. This teaching needs to be inserted into medical curricula in different ways, notably into core curricula, a special overseas doctor track, optional student selected components, elective programmes, optional intercalated degrees and postgraduate study. SUMMARY: We argue that teaching of global health in undergraduate medical curricula must respond to changing understandings of the term global health. In particular it must be taught from the perspective of more disciplines than just biomedicine, in order to reflect the social, political and economic causes of ill health. In this way global health can provide valuable training for all doctors, whether they choose to remain in their countries of origin or work abroad.
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Currículo/tendências , Educação de Graduação em Medicina/tendências , Saúde Global , Humanos , Internacionalidade , Inquéritos e QuestionáriosRESUMO
To achieve universal health coverage, health system strengthening (HSS) is required to support the of delivery of high-quality care. The aim of the National Institute for Health Research Global Research Unit on HeAlth System StrEngThening in Sub-Saharan Africa (ASSET) is to address this need in a four-year programme, with three healthcare platforms involving eight work-packages. Key to effective health system strengthening (HSS) is the pre-implementation phase of research where efforts focus on applying participatory methods to embed the research programme within the existing health system. To conceptualise the approach, we provide an overview of the key methods applied across work-package to address this important phase of research conducted between 2017 and 2021.Work-packages are being undertaken in publicly funded health systems in rural and urban areas in Ethiopia, Sierra Leone, South Africa, and Zimbabwe. Stakeholders including patients and their caregivers, community representatives, clinicians, managers, administrators, and policymakers are the main research participants.In each work-package, initial activities engage stakeholders and build relationships to ensure co-production and ownership of HSSIs. A mixed-methods approach is then applied to understand and address determinants of high-quality care delivery. Methods such as situation analysis, cross-sectional surveys, interviews and focus group discussions are adopted to each work-package aim and context. At the end of the pre-implementation phase, findings are disseminated using focus group discussions and participatory Theory of Change workshops where stakeholders from each work package use findings to select HSSIs and develop a programme theory.ASSET places a strong emphasis of the pre-implementation phase in order to provide an in-depth and systematic diagnosis of the existing heath system functioning, needs for strengthening and stakeholder engagement. This common approach will inform the design and evaluation of the HSSIs to increase effectiveness across work packages and contexts, to better understand what works, for whom, and how.
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Atenção à Saúde , Programas Governamentais , Estudos Transversais , Humanos , Recém-Nascido , Assistência Médica , Atenção Primária à SaúdeRESUMO
Supermassive black holes underwent periods of exponential growth during which we see them as quasars in the distant Universe. The summed emission from these quasars generates the cosmic X-ray background, the spectrum of which has been used to argue that most black-hole growth is obscured. There are clear examples of obscured black-hole growth in the form of 'type-2' quasars, but their numbers are fewer than expected from modelling of the X-ray background. Here we report the direct detection of a population of distant type-2 quasars, which is at least comparable in size to the well-known unobscured type-1 population. We selected objects that have mid-infrared and radio emissions characteristic of quasars, but which are faint at near-infrared and optical wavelengths. We conclude that this population is responsible for most of the black-hole growth in the young Universe and that, throughout cosmic history, black-hole growth occurs in the dusty, gas-rich centres of active galaxies.
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We examined the views of providers and users of the surgical system in Freetown, Sierra Leone on processes of care, job and service satisfaction and barriers to achieving quality and accessible care, focusing particularly on the main public tertiary hospital in Freetown and two secondary and six primary sites from which patients are referred to it. We conducted interviews with health care providers (N = 66), service users (n = 24) and people with a surgical condition who had chosen not to use the public surgical system (N = 13), plus two focus groups with health providers in primary care (N = 10 and N = 10). The overall purpose of the study was to understand perceptions on processes of and barriers to care from a variety of perspectives, to recommend interventions to improve access and quality of care as part of a larger study. Our research suggests that providers perceive their relationships with patients to be positive, while the majority of patients see the opposite: that many health workers are unapproachable and uncaring, particularly towards poorer patients who are unable or unwilling to pay staff extra in the form of informal payments for their care. Many health care providers note the importance of lack of recognition shown to them by their superiors and the health system in general. We suggest that this lack of recognition underlies poor morale, leading to poor care. Any intervention to improve the system should therefore consider staff-patient relations as a key element in its design and implementation, and ideally be led and supported by frontline healthcare workers.
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Atitude do Pessoal de Saúde , Pessoal de Saúde , Grupos Focais , Humanos , Pesquisa Qualitativa , Serra LeoaRESUMO
OBJECTIVES: Prevalence of cardiovascular disease risk factors (CVDRF) is increasing, especially in low-income countries. In Sierra Leone, there are no previous studies on the knowledge and the awareness of these conditions in the community. This study aimed to explore the knowledge and understanding of CVDRF, as well as the perceptions of the barriers and facilitators to accessing care for these conditions, among patients and community leaders in Sierra Leone. DESIGN: Qualitative study employing semistructured interviews and focus group discussions. SETTING: Urban and rural Bo District, Sierra Leone. PARTICIPANTS: Interviews with a purposive sample of 37 patients and two focus groups with six to nine community leaders. RESULTS: While participants possessed general knowledge of their conditions, the level and complexity of this knowledge varied widely. There were clear gaps in knowledge regarding the coexistence of CVDRF and their consequences, as well as the link between behavioural factors and CVDRF. An overarching theme from the data was the need to create an understanding and awareness of CVDRF in the community in order to prevent and improve management of these conditions. Cost was also seen as a major barrier to accessing care for CVDRFs. CONCLUSIONS: The knowledge gaps identified in this study highlight the need to design strategies and interventions that improve knowledge and recognition of CVDRF in the community. Interventions should specifically consider how to develop and enhance awareness about CVDRF and their consequences. They should also consider how patients seek help and where they access it.