104 research outputs found
X--Ray Spectra from Neutron Stars Accreting at Low Rates
The spectral properties of X--ray radiation produced in a static atmosphere
around a neutron star accreting at very low rates are investigated. Previous
results by Alme \& Wilson (1973) are extended to the range to include the typical luminosities, , expected from isolated neutron stars
accreting the interstellar medium. The emergent spectra show an overall
hardening with respect to the blackbody at the neutron star effective
temperature in addition to a significant excess over the Wien tail. The
relevance of present results in connection with the observability of
low--luminosity X--ray sources is briefly discussed.Comment: 14 pages (3 postscript figures available on request), PlainTex,
submitted to Ap
X-ray study of HLX1: intermediate-mass black hole or foreground neutron star?
We re-assess the XMM-Newton and Swift observations of HLX1, to examine the
evidence for its identification as an intermediate-mass black hole. We show
that the X-ray spectral and timing properties are equally consistent with an
intermediate-mass black hole in a high state, or with a foreground neutron star
with a luminosity of about a few times 10^{32} erg/s ~ 10^{-6} L_{Edd}, located
at a distance of about 1.5 to 3 kpc. Contrary to previously published results,
we find that the X-ray spectral change between the two XMM-Newton observations
of 2004 and 2008 (going from power-law dominated to thermal dominated) is not
associated with a change in the X-ray luminosity. The thermal component becomes
more dominant (and hotter) during the 2009 outburst seen by Swift, but in a way
that is consistent with either scenario.Comment: 10 pages, accepted by MNRAS. Corrected LZ's affiliation and updated 1
referenc
Hypospadias anatomy: Elastosonographic evaluation of the normal and hypospadic penis
Background Hypospadias is one of the most common congenital anomalies in childhood. The aim of this study is to apply elastosonography on normal and hypospadic penis to verify the structural differences in tissues composition and stiffness. Materials and methods We analyzed medical chart of patients treated at our Institution for hypospadias during the period December 2005 and December 2014 (group 1). Other two groups were enrolled for this study: group 2- patients with hypospadias waiting for surgery and group 3-patients without hypospadias. Inclusion and exclusion criteria were created; all patients underwent penile ultrasound and elastosonography. Elastographic index of elasticity was defined as soft, medium-hard or hard. We assigned the value 1 to soft tissue, 2 and 3 to medium-hard and hard respectively. Results During the study period 294 patients were treated for hypospadias. After reviewing medical chart 115 patients were considered for analysis (group 1). 22 patients were enrolled in group 2 and 38 patients were enrolled in group 3. Group 1: 7 proximal hypospadias, 29 penile hypospadias, 79 distal hypospadias. Patients with hypospadias had malformation also at corpus spongiosum and cavernosum respect to controls. Elastography showed a corpus spongiosum stiffness defined as medium-hard or hard in all cases of the pathologic group and soft in all the subjects of the control group (p < 0.05). Conclusions Elastosonography showed how the hypospadia anatomy is deeply altered, even in an anatomical area far from meatal abnormality: corpus spongiosum in hypospadic penis seems to be globally stiffer and less elastic and cavernous corpora are less developed.[Figure presented
A unified compendium of prokaryotic and viral genomes from over 300 anaerobic digestion microbiomes
BackgroundThe anaerobic digestion process degrades organic matter into simpler compounds and occurs in strictly anaerobic and microaerophilic environments. The process is carried out by a diverse community of microorganisms where each species has a unique role and it has relevant biotechnological applications since it is used for biogas production. Some aspects of the microbiome, including its interaction with phages, remains still unclear: a better comprehension of the community composition and role of each species is crucial for a cured understanding of the carbon cycle in anaerobic systems and improving biogas production.ResultsThe primary objective of this study was to expand our understanding on the anaerobic digestion microbiome by jointly analyzing its prokaryotic and viral components. By integrating 192 additional datasets into a previous metagenomic database, the binning process generated 11,831 metagenome-assembled genomes from 314 metagenome samples published between 2014 and 2022, belonging to 4,568 non-redundant species based on ANI calculation and quality verification. CRISPR analysis on these genomes identified 76 archaeal genomes with active phage interactions. Moreover, single-nucleotide variants further pointed to archaea as the most critical members of the community. Among the MAGs, two methanogenic archaea, Methanothrix sp. 43zhSC_152 and Methanoculleus sp. 52maCN_3230, had the highest number of SNVs, with the latter having almost double the density of most other MAGs.ConclusionsThis study offers a more comprehensive understanding of microbial community structures that thrive at different temperatures. The findings revealed that the fraction of archaeal species characterized at the genome level and reported in public databases is higher than that of bacteria, although still quite limited. The identification of shared spacers between phages and microbes implies a history of phage-bacterial interactions, and specifically lysogenic infections. A significant number of SNVs were identified, primarily comprising synonymous and nonsynonymous variants. Together, the findings indicate that methanogenic archaea are subject to intense selective pressure and suggest that genomic variants play a critical role in the anaerobic digestion process. Overall, this study provides a more balanced and diverse representation of the anaerobic digestion microbiota in terms of geographic location, temperature range and feedstock utilization
Genetic Testing and Counselling in Hypertrophic Cardiomyopathy: Frequently Asked Questions
Genetic counselling and genetic testing in hypertrophic cardiomyopathy (HCM) represent an integral part of the diagnostic algorithm to confirm the diagnosis, distinguish it from phenocopies, and suggest tailored therapeutic intervention strategies. Additionally, they enable cascade genetic testing in the family. With the implementation of Next Generation Sequencing technologies (NGS), the interpretation of genetic data has become more complex. In this regard, cardiologists play a central role, aiding geneticists to correctly evaluate the pathogenicity of the identified genetic alterations. In the ideal setting, geneticists and cardiologists must work side by side to diagnose HCM as well as convey the correct information to patients in response to their many questions and concerns. After a brief overview of the role of genetics in the diagnosis of HCM, we present and discuss the frequently asked questions by HCM patients throughout our 20-year genetic counselling experience. Appropriate communication between the team and the families is key to the goal of delivering the full potential of genetic testing to our patients
Inclusão Digital: Avaliação dos Impactos de uma Política Pública de Inclusão Digital da Região Central do Rio Grande do Sul
O presente estudo investigou mudanças acarretadas pela inclusão digital, fossem essas individuais ou coletivas. Para tanto, foi realizada uma pesquisa de caráter qualitativa e natureza exploratória, utilizando, para coleta de dados, entrevistas semiestruturadas. O protocolo de entrevista teve como base o Modelo de Avaliação de Programas de Inclusão Digital e Social (MAPIDS), desenvolvido por Brandão (2009), e passou pela avaliação de uma especialista e por pré-teste para equação do vocabulário e ajustes quanto a objetividade das questões. Foram entrevistados 10 beneficiados do projeto de inclusão digital promovido por uma Fundação da Região Central do Estado do Rio Grande do Sul. Os resultados evidenciaram que a satisfação dos beneficiados foi proporcionada pelo ambiente agradável e propicio ao cumprimento da proposta de aprendizado, alicerçado pela infraestrutura tecnológica adequada. Como contribuição desse trabalho cita-se a emersão de uma variável exploratória, didática, possibilitando a ampliação do modelo de avaliação de uma política pública, proposto por Brandão (2009)
The Hot and Energetic Universe: End points of stellar evolution
White dwarfs, neutron stars and stellar mass black holes are key laboratories
to study matter in most extreme conditions of gravity and magnetic field. The
unprecedented effective area of Athena+ will allow us to advance our
understanding of emission mechanisms and accretion physics over a wide range of
mass accretion rates, starting from lower and sub-luminous quiescent X-ray
binaries up to super-Eddington ultra-luminous sources. Athena+ will measure
stellar black hole spins in a much higher number of binaries than achievable
now, opening the possibility to study how spin varies with black hole history.
The high throughput and energy resolution of the X-IFU will be instrumental in
establishing how disc wind properties depend on accretion state, in determining
wind launching mechanism and in quantifying the impact of the wind induced mass
loss on binary evolution and environment. Triggers and high quality optical and
radio data originating from large wide field contemporaneous instruments will
provide essential complementary information on jet launching mechanisms and on
the physics of rotation powered pulsars, for instance. In addition, Athena+
will furnish multiple, independent measurements of the neutron star mass/radius
relation in a wide range of environments and conditions so as to constrain the
debated equation of state.Comment: Supporting paper for the science theme "The Hot and Energetic
Universe" to be implemented by the Athena+ X-ray observatory
(http://www.the-athena-x-ray-observatory.eu). 9 pages, 4 figure
Sensitivity and specificity of in vivo COVID-19 screening by detection dogs: Results of the C19-Screendog multicenter study
Trained dogs can recognize the volatile organic compounds contained in biological samples of
patients with COVID-19 infection. We assessed the sensitivity and specificity of in vivo SARS-CoV-
2 screening by trained dogs.
We recruited five dog-handler dyads. In the operant conditioning phase, the dogs were taught to
distinguish between positive and negative sweat samples collected from volunteers’ underarms in
polymeric tubes. The conditioning was validated by tests involving 16 positive and 48 negative
samples held or worn in such a way that the samples were invisible to the dog and handler. In the
screening phase the dogs were led by their handlers to a drive-through facility for in vivo screening
of volunteers who had just received a nasopharyngeal swab from nursing staff. Each volunteer who
had already swabbed was subsequently tested by two dogs, whose responses were recorded as
positive, negative, or inconclusive. The dogs’ behavior was constantly monitored for attentiveness
and wellbeing.
All the dogs passed the conditioning phase, their responses showing a sensitivity of 83-100% and a
specificity of 94-100%. The in vivo screening phase involved 1251 subjects, of whom 205 had a
COVID-19 positive swab and two dogs per each subject to be screened. Screeningsensitivity and
specificity were respectively 91.6-97.6% and 96.3-100% when only one dog was involved, whereas
combined screening by two dogs provided a higher sensitivity. Dog wellbeing was also analysed:
monitoring of stress and fatigue suggested that the screening activity did not adversely impact the
dogs’ wellbeing. This work, by screening a large number of subjects, strengthen recent findings that
trained dogs can discriminate between COVID-19 infected and healthy human subjects and introduce
two novel research aspects: i) assessement of signs of fatigue and stress in dogs during training and
testing, and ii) combining screening by two dogs to improve detection sensitivity and specificity.
Using some precautions to reduce the risk of infection and spillover, in vivo COVID-19 screening by
a dog-handler dyad can be suitable to quickly screen large numbers of people: it is rapid, non-
invasiveand economical, since it does not involve actual sampling, lab resources or waste
management, and is suitable to screen large numbers of people
Evaluation of the 2021 ESC recommendations for family screening in hereditary transthyretin cardiac amyloidosis
AIMS: The 2021 European Society of Cardiology (ESC) screening recommendations for individuals carrying a pathogenic transthyretin amyloidosis variant (ATTRv) are based on expert opinion. We aimed to (i) determine the penetrance of ATTRv cardiomyopathy (ATTRv-CM) at baseline; (ii) examine the value of serial evaluation; and (iii) establish the yield of first-line diagnostic tests (i.e. electrocardiogram, echocardiogram, and laboratory tests) as per 2021 ESC position statement.METHODS AND RESULTS: We included 159 relatives (median age 55.6 [43.2-65.9] years, 52% male) at risk for ATTRv-CM from 10 centres. The primary endpoint, ATTRv-CM diagnosis, was defined as the presence of (i) cardiac tracer uptake in bone scintigraphy; or (ii) transthyretin-positive cardiac biopsy. The secondary endpoint was a composite of heart failure (New York Heart Association class ≥II) and pacemaker-requiring conduction disorders. At baseline, 40/159 (25%) relatives were diagnosed with ATTRv-CM. Of those, 20 (50%) met the secondary endpoint. Indication to screen (≤10 years prior to predicted disease onset and absence of extracardiac amyloidosis) had an excellent negative predictive value (97%). Other pre-screening predictors for ATTRv-CM were infrequently identified variants and male sex. Importantly, 13% of relatives with ATTRv-CM did not show any signs of cardiac involvement on first-line diagnostic tests. The yield of serial evaluation (n = 41 relatives; follow-up 3.1 [2.2-5.2] years) at 3-year interval was 9.4%.CONCLUSIONS: Screening according to the 2021 ESC position statement performs well in daily clinical practice. Clinicians should adhere to repeating bone scintigraphy after 3 years, as progressing to ATTRv-CM without signs of ATTRv-CM on first-line diagnostic tests or symptoms is common.</p
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