The magnetic nature of disk accretion onto black holes

Although disk accretion onto compact objects - white dwarfs, neutron stars, and black holes - is central to much of high energy astrophysics, the mechanisms which enable this process have remained observationally elusive. Accretion disks must transfer angular momentum for matter to travel radially inward onto the compact object. Internal viscosity from magnetic processes and disk winds can in principle both transfer angular momentum, but hitherto we lacked evidence that either occurs. Here we report that an X-ray-absorbing wind discovered in an observation of the stellar-mass black hole binary GRO J1655-40 must be powered by a magnetic process that can also drive accretion through the disk. Detailed spectral analysis and modeling of the wind shows that it can only be powered by pressure generated by magnetic viscosity internal to the disk or magnetocentrifugal forces. This result demonstrates that disk accretion onto black holes is a fundamentally magnetic process.Comment: 15 pages, 2 color figures, accepted for publication in Nature. Supplemental materials may be obtained by clicking http://www.astro.lsa.umich.edu/~jonmm/nature1655.p

Feedback and the Formation of Dwarf Galaxy Stellar Halos

Stellar population studies show that low mass galaxies in all environments exhibit stellar halos that are older and more spherically distributed than the main body of the galaxy. In some cases, there is a significant intermediate age component that extends beyond the young disk. We examine a suite of Smoothed Particle Hydrodynamic (SPH) simulations and find that elevated early star formation activity combined with supernova feedback can produce an extended stellar distribution that resembles these halos for model galaxies ranging from $v_{200}$ = 15 km s$^{-1}$ to 35 km s$^{-1}$, without the need for accretion of subhalos.Comment: 15 pages, 15 figures, accepted MNRA

The Trypanosoma cruzi Sylvio X10 strain maxicircle sequence: the third musketeer

<p>Abstract</p> <p>Background</p> <p>Chagas disease has a diverse pathology caused by the parasite <it>Trypanosoma cruzi</it>, and is indigenous to Central and South America. A pronounced feature of the trypanosomes is the kinetoplast, which is comprised of catenated maxicircles and minicircles that provide the transcripts involved in uridine insertion/deletion RNA editing. <it>T. cruzi </it>exchange genetic material through a hybridization event. Extant strains are grouped into six discrete typing units by nuclear markers, and three clades, A, B, and C, based on maxicircle gene analysis. Clades A and B are the more closely related. Representative clade B and C maxicircles are known in their entirety, and portions of A, B, and C clades from multiple strains show intra-strain heterogeneity with the potential for maxicircle taxonomic markers that may correlate with clinical presentation.</p> <p>Results</p> <p>To perform a genome-wide analysis of the three maxicircle clades, the coding region of clade A representative strain Sylvio X10 (a.k.a. Silvio X10) was sequenced by PCR amplification of specific fragments followed by assembly and comparison with the known CL Brener and Esmeraldo maxicircle sequences. The clade A rRNA and protein coding region maintained synteny with clades B and C. Amino acid analysis of non-edited and 5'-edited genes for Sylvio X10 showed the anticipated gene sequences, with notable frameshifts in the non-edited regions of Cyb and ND4. Comparisons of genes that undergo extensive uridine insertion and deletion display a high number of insertion/deletion mutations that are likely permissible due to the post-transcriptional activity of RNA editing.</p> <p>Conclusion</p> <p>Phylogenetic analysis of the entire maxicircle coding region supports the closer evolutionary relationship of clade B to A, consistent with uniparental mitochondrial inheritance from a discrete typing unit TcI parental strain and studies on smaller fragments of the mitochondrial genome. Gene variance that can be corrected by RNA editing hints at an unusual depth for maxicircle taxonomic markers, which will aid in the ability to distinguish strains, their corresponding symptoms, and further our understanding of the <it>T. cruzi </it>population structure. The prevalence of apparently compromised coding regions outside of normally edited regions hints at undescribed but active mechanisms of genetic exchange.</p

ENFERMAGEM DO TRABALHO: UMA REVISÃO INTEGRATIVA ACERCA DA ATIVIDADE PROFISSIONAL DO ENFERMEIRO NO PERÍODO PANDEMICO

Occupational nurses play a fundamental role in identifying occupational risks, carrying out medical examinations and educating workers about preventive measures. They also contribute to the analysis of environmental risks, accident prevention, mental health promotion and ergonomic adaptation. During the Covid-19 pandemic, occupational nursing has been crucial in implementing education, prevention and control measures. Objective: to describe the scientific evidence available in national and international literature regarding the professional activity of Occupational Nurses during the Covid-19 pandemic. Method: The methodology adopted was based on extensive research in academic databases, such as PubMed, Scopus and Google Scholar, using relevant keywords related to occupational nursing, occupational health and safety at work. Result: Occupational nursing plays a crucial role in preventing occupational diseases through the identification and control of risks present in work environments, promotion and safety of workers. Discussion: The challenges faced by occupational nursing were observed, such as the lack of adequate resources to carry out their activities effectively, personal protective equipment, limited access to complementary exams and inadequate infrastructure in the workplace. And the need for integration between occupational nursing and other segments of occupational health. Conclusion: Occupational nursing plays a key role in promoting and preserving the health of employees, as well as preventing occupational diseases.La enfermera ocupacional juega un papel fundamental en la identificación de riesgos laborales, la realización de exámenes médicos y la educación de los trabajadores sobre las medidas preventivas. También contribuyen al análisis de riesgos ambientales, la prevención de accidentes, la promoción de la salud mental y la adaptación ergonómica. Durante la pandemia de Covid-19, la enfermería ocupacional ha sido crucial en la implementación de medidas de educación, prevención y control. Objetivo: describir la evidencia científica disponible en la literatura nacional e internacional sobre la actividad profesional de la Enfermería Ocupacional durante la pandemia Covid-19. Método: La metodología adoptada se basó en una extensa investigación en bases de datos académicas, como PubMed, Scopus y Google Scholar, utilizando palabras clave relevantes relacionadas con enfermería ocupacional, salud ocupacional y seguridad en el trabajo. Resultado: La enfermería ocupacional juega un papel crucial en la prevención de enfermedades profesionales a través de la identificación y control de los riesgos presentes en los ambientes laborales, la promoción y la seguridad de los trabajadores. Discusión: Se observaron los desafíos que enfrenta la enfermería ocupacional, como la falta de recursos adecuados para realizar sus actividades de manera efectiva, equipos de protección personal, acceso limitado a exámenes complementarios e infraestructura inadecuada en el lugar de trabajo. Y la necesidad de integración entre la enfermería ocupacional y otros segmentos de la salud ocupacional. Conclusión: La enfermería ocupacional juega un papel clave en la promoción y preservación de la salud de los empleados, así como en la prevención de enfermedades profesionales.Os enfermeiros do trabalho desempenham um  papel fundamental na identificação de riscos ocupacionais, na realização de exames de saúde e na educação dos trabalhadores sobre medidas preventivas. Eles também contribuem para a análise de riscos ambientais, prevenção de acidentes, promoção da saúde mental e adequação ergonômica. Durante a pandemia de Covid-19, a enfermagem do trabalho tem sido crucial na implementação de medidas de educação, prevenção e controle. Objetivo: descrever as evidências científicas disponíveis na literatura nacional e internacional acerca da atividade profissional do Enfermeiro do Trabalho durante a pandemia de Covid-19. Métodos: O método adotado baseou-se em uma ampla pesquisa em bases de dados acadêmicas, como PubMed, Scopus e Google Scholar, utilizando palavras-chave relevantes relacionadas à enfermagem do trabalho, saúde ocupacional e segurança no trabalho. Resultados: A enfermagem do trabalho desempenha um papel crucial na prevenção de doenças ocupacionais por meio da identificação e controle dos riscos presentes nos ambientes de trabalho, promoção e segurança dos trabalhadores. Discussão: Observou-se os desafios enfrentados pela enfermagem do trabalho, como a falta de recursos adequados para realizar suas atividades de forma eficaz, de equipamentos de proteção individual, acesso limitado a exames complementares e infraestrutura inadequada nos locais de trabalho. E a necessidade de integração entre a enfermagem do trabalho e os demais seguimentos da saúde ocupacional. Conclusão: A enfermagem ocupacional exerce um papel primordial na promoção e preservação da saúde dos colaboradores, assim como na prevenção de patologias laborais.Introdução: Os enfermeiros do trabalho desempenham um  papel fundamental na identificação de riscos ocupacionais, na realização de exames de saúde e na educação dos trabalhadores sobre medidas preventivas. Eles também contribuem para a análise de riscos ambientais, prevenção de acidentes, promoção da saúde mental e adequação ergonômica. Durante a pandemia de COVID-19, a enfermagem do trabalho tem sido crucial na implementação de medidas de educação, prevenção e controle. Objetivo: descrever as evidências científicas disponíveis na literatura nacional e internacional acerca da atividade profissional do Enfermeiro do Trabalho durante a pandemia de Covid-19. Métodos: O método adotado baseou-se em uma ampla pesquisa em bases de dados acadêmicas, como PubMed, Scopus e Google Scholar, utilizando palavras-chave relevantes relacionadas à enfermagem do trabalho, saúde ocupacional e segurança no trabalho. Resultados: A enfermagem do trabalho desempenha um papel crucial na prevenção de doenças ocupacionais por meio da identificação e controle dos riscos presentes nos ambientes de trabalho, promoção e segurança dos trabalhadores. Discussão: Observou-se os desafios enfrentados pela enfermagem do trabalho, como a falta de recursos adequados para realizar suas atividades de forma eficaz, de equipamentos de proteção individual, acesso limitado a exames complementares e infraestrutura inadequada nos locais de trabalho. E a necessidade de integração entre a enfermagem do trabalho e os demais seguimentos da saúde ocupacional. Conclusão: A enfermagem ocupacional exerce um papel primordial na promoção e preservação da saúde dos colaboradores, assim como na prevenção de patologias laborais

Computerized clinical decision support systems for therapeutic drug monitoring and dosing: A decision-maker-researcher partnership systematic review

<p>Abstract</p> <p>Background</p> <p>Some drugs have a narrow therapeutic range and require monitoring and dose adjustments to optimize their efficacy and safety. Computerized clinical decision support systems (CCDSSs) may improve the net benefit of these drugs. The objective of this review was to determine if CCDSSs improve processes of care or patient outcomes for therapeutic drug monitoring and dosing.</p> <p>Methods</p> <p>We conducted a decision-maker-researcher partnership systematic review. Studies from our previous review were included, and new studies were sought until January 2010 in MEDLINE, EMBASE, Evidence-Based Medicine Reviews, and Inspec databases. Randomized controlled trials assessing the effect of a CCDSS on process of care or patient outcomes were selected by pairs of independent reviewers. A study was considered to have a positive effect (<it>i.e.</it>, CCDSS showed improvement) if at least 50% of the relevant study outcomes were statistically significantly positive.</p> <p>Results</p> <p>Thirty-three randomized controlled trials were identified, assessing the effect of a CCDSS on management of vitamin K antagonists (14), insulin (6), theophylline/aminophylline (4), aminoglycosides (3), digoxin (2), lidocaine (1), or as part of a multifaceted approach (3). Cluster randomization was rarely used (18%) and CCDSSs were usually stand-alone systems (76%) primarily used by physicians (85%). Overall, 18 of 30 studies (60%) showed an improvement in the process of care and 4 of 19 (21%) an improvement in patient outcomes. All evaluable studies assessing insulin dosing for glycaemic control showed an improvement. In meta-analysis, CCDSSs for vitamin K antagonist dosing significantly improved time in therapeutic range.</p> <p>Conclusions</p> <p>CCDSSs have potential for improving process of care for therapeutic drug monitoring and dosing, specifically insulin and vitamin K antagonist dosing. However, studies were small and generally of modest quality, and effects on patient outcomes were uncertain, with no convincing benefit in the largest studies. At present, no firm recommendation for specific systems can be given. More potent CCDSSs need to be developed and should be evaluated by independent researchers using cluster randomization and primarily assess patient outcomes related to drug efficacy and safety.</p

Quantitative-spatial assessment of soil contamination in S. Francisco de Assis due to mining activity of the Panasqueira mine (Portugal)

Through the years, mining and beneficiation processes produces large amounts of As-rich mine wastes laid up in huge tailings and open-air impoundments (Barroca Grande and Rio tailings) that are the main source of pollution in the surrounding area once they are exposed to the weathering conditions leading to the formation of AMD and consequently to the contamination of the surrounding environments, in particularly soils. In order to investigate the environmental contamination impact on S. Francisco de Assis (village located between the two major impoundments and tailings) agricultural soils, a geochemical survey was undertaken to assess toxic metals associations, related levels and their spatial distribution, and to identify the possible contamination sources. According to the calculated contamination factor, As and Zn have a very high contamination factor giving rise to 65.4 % of samples with a moderate to high pollution degree; 34.6 % have been classified as nil to very low pollution degree. The contamination factor spatial distribution put in evidence the fact that As, Cd, Cu, Pb, and Zn soils contents, downstream Barroca Grande tailing, are increased when compared with the local Bk soils. The mechanical dispersion, due to erosion, is the main contamination source. The chemical extraction demonstrates that the trace metals distribution and accumulation in S. Francisco de Assis soils is related to sulfides, but also to amorphous or poorly crystalline iron oxide phases. The partitioning study allowed understanding the local chemical elements mobility and precipitation processes, giving rise to the contamination dispersion model of the study area. The wind and hydrological factors are responsible for the chemical elements transport mechanisms, the water being the main transporter medium and soils as one of the possible retention media

Erratum to : Analysis of the mitochondrial maxicircle of Trypanosoma lewisi, a neglected human pathogen

BACKGROUND The haemoflagellate Trypanosoma lewisi is a kinetoplastid parasite which, as it has been recently reported to cause human disease, deserves increased attention. Characteristic features of all kinetoplastid flagellates are a uniquely structured mitochondrial DNA or kinetoplast, comprised of a network of catenated DNA circles, and RNA editing of mitochondrial transcripts. The aim of this study was to describe the kinetoplast DNA of T. lewisi. METHODS/RESULTS In this study, purified kinetoplast DNA from T. lewisi was sequenced using high-throughput sequencing in combination with sequencing of PCR amplicons. This allowed the assembly of the T. lewisi kinetoplast maxicircle DNA, which is a homologue of the mitochondrial genome in other eukaryotes. The assembly of 23,745 bp comprises the non-coding and coding regions. Comparative analysis of the maxicircle sequence of T. lewisi with Trypanosoma cruzi, Trypanosoma rangeli, Trypanosoma brucei and Leishmania tarentolae revealed that it shares 78 %, 77 %, 74 % and 66 % sequence identity with these parasites, respectively. The high GC content in at least 9 maxicircle genes of T. lewisi (ATPase6; NADH dehydrogenase subunits ND3, ND7, ND8 and ND9; G-rich regions GR3 and GR4; cytochrome oxidase subunit COIII and ribosomal protein RPS12) implies that their products may be extensively edited. A detailed analysis of the non-coding region revealed that it contains numerous repeat motifs and palindromes. CONCLUSIONS We have sequenced and comprehensively annotated the kinetoplast maxicircle of T. lewisi. Our analysis reveals that T. lewisi is closely related to T. cruzi and T. brucei, and may share similar RNA editing patterns with them rather than with L. tarentolae. These findings provide novel insight into the biological features of this emerging human pathogen

An evolving jet from a strongly magnetized accreting X-ray pulsar

© 2018, Springer Nature Limited. Relativistic jets are observed throughout the Universe and strongly affect their surrounding environments on a range of physical scales, from Galactic binary systems1 to galaxies and clusters of galaxies2. All types of accreting black hole and neutron star have been observed to launch jets3, with the exception of neutron stars with strong magnetic fields4,5 (higher than 1012 gauss), leading to the conclusion that their magnetic field strength inhibits jet formation6. However, radio emission recently detected from two such objects could have a jet origin, among other possible explanations7,8, indicating that this long-standing idea might need to be reconsidered. But definitive observational evidence of such jets is still lacking. Here we report observations of an evolving jet launched by a strongly magnetized neutron star accreting above the theoretical maximum rate given by the Eddington limit. The radio luminosity of the jet is two orders of magnitude fainter than those seen in other neutron stars with similar X-ray luminosities9, implying an important role for the properties of the neutron star in regulating jet power. Our result also shows that the strong magnetic fields of ultra-luminous X-ray pulsars do not prevent such sources from launching jets

A major QTL controlling apple skin russeting maps on the linkage group 12 of 'Renetta Grigia di Torriana'

Background: Russeting is a disorder developed by apple fruits that consists of cuticle cracking followed by the replacement of the epidermis by a corky layer that protects the fruit surface from water loss and pathogens. Although influenced by many environmental conditions and orchard management practices, russeting is under genetic control. The difficulty in classifying offspring and consequent variable segregation ratios have led several authors to conclude that more than one genetic determinant could be involved, although some evidence favours a major gene (Ru). Results: In this study we report the mapping of a major genetic russeting determinant on linkage group 12 of apple as inferred from the phenotypic observation in a segregating progeny derived from 'Renetta Grigia di Torriana', the construction of a 20 K Illumina SNP chip based genetic map, and QTL analysis. Recombination analysis in two mapping populations restricted the region of interest to approximately 400 Kb. Of the 58 genes predicted from the Golden Delicious sequence, a putative ABCG family transporter has been identified. Within a small set of russeted cultivars tested with markers of the region, only six showed the same haplotype of 'Renetta Grigia di Torriana'. Conclusions: A major determinant (Ru_RGT) for russeting development putatively involved in cuticle organization is proposed as a candidate for controlling the trait. SNP and SSR markers tightly co-segregating with the Ru_RGT locus may assist the breeder selection. The observed segregations and the analysis of the 'Renetta Grigia di Torriana' haplotypic region in a panel of russeted and non-russeted cultivars may suggest the presence of other determinants for russeting in apple