Absolute colors and phase coefficients of asteroids

Context: We use phase curves of small bodies to measure absolute magnitudes and, together with complementary theoretical and laboratory results, to understand their surfaces' micro and macroscopic properties. Although we can observe asteroids up to phase angles of about 30 deg, the range of phase angles covered by outer solar system objects usually does not go further than 7 to 10 deg for centaurs and 2 deg for trans-Neptunian objects, and a linear relation between magnitude and phase angle may be assumed. Aims: We aim at directly comparing data taken for objects in the inner solar system (inside the orbit of Jupiter) with data of centaurs and trans-Neptunian objects. Methods: We use the SLOAN Moving Objects Catalog data to construct phase curves restricted to phase angles less than or equal to 7.5 deg, compatible with the angles observed for the trans-Neptunian/Centaur population. We assume a linear model for the photometric behavior to obtain absolute magnitudes and phase coefficients in the ugirz, V, and R filters. Results: We obtained absolute magnitudes in seven filters for $>4000$ objects. Our comparison with outer solar system objects points to a common property of the surfaces: intrinsically redder objects become blue with increasing phase angle, while the opposite happens for intrinsically bluer objects.Comment: 8 pages, 11 figures, 1 appendix, accepted for publication in A&

On the Duality Between Retinex and Image Dehazing

Image dehazing deals with the removal of undesired loss of visibility in outdoor images due to the presence of fog. Retinex is a color vision model mimicking the ability of the Human Visual System to robustly discount varying illuminations when observing a scene under different spectral lighting conditions. Retinex has been widely explored in the computer vision literature for image enhancement and other related tasks. While these two problems are apparently unrelated, the goal of this work is to show that they can be connected by a simple linear relationship. Specifically, most Retinex-based algorithms have the characteristic feature of always increasing image brightness, which turns them into ideal candidates for effective image dehazing by directly applying Retinex to a hazy image whose intensities have been inverted. In this paper, we give theoretical proof that Retinex on inverted intensities is a solution to the image dehazing problem. Comprehensive qualitative and quantitative results indicate that several classical and modern implementations of Retinex can be transformed into competing image dehazing algorithms performing on pair with more complex fog removal methods, and can overcome some of the main challenges associated with this problem

Allele and haplotype frequencies of HLA-A, -B, -C, -DRB1, -DQB1 and -DQA1 in Castile and Leon region from North West of Spain

HLA studies have been used to determine the admixture of different populations within the Iberian Peninsula including neighbouring regions with shared origins, such as Portugal and Castile and Leon. These studies certainly can be used to study human migration that could establish populations currently settled according to genetic distant analysis based on the HLA diversity and language variety.This work was supported by the “Gerencia Regional de Salud de Castilla y Leon” (GRS 2080/A/19, 2019) and (GRS COVID 70/A/20, 2020)

Adenosine Deaminase Activity Is a Sensitive Marker for the Diagnosis of Tuberculous Pleuritis in Patients with Very Low CD4 Counts

Background: Adenosine Deaminase Activity (ADA) is a commonly used marker for the diagnosis of tuberculous pleural effusion. There has been concern about its usefulness in immunocompromised patients, especially HIV positive patients with very low CD4 counts. The objective of this study was to evaluate the sensitivity of ADA in pleural fluid in patients with low CD4 counts. Materials and Methods: This was a retrospective case control study. Medical files of patients with tuberculous pleuritis and non-tuberculous pleuritis were reviewed. Clinical characteristics, CD4 cell counts in blood and biochemical markers in pleural fluid, including ADA were recorded. Results: One ninety seven tuberculous pleuritis and 40 non- tuberculous pleuritis patients were evaluated. Using the cut-off value of 30 U/L, the overall sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of ADA was 94%, 95%, 19, and 0.06 respectively. The mean CD4 cell counts among TB pleuritis patients was 29 and 153 cells/microL in patients with CD4 ,50 cells/microL and .50 cells/microL, (p,0.05) respectively. The corresponding mean ADA values for these patients were 76 U/L and 72 U/L respectively (p.0.5). There was no correlation between ADA values and CD4 cell counts (r =20.120, p = 0.369). Conclusion: ADA analysis is a sensitive marker of tuberculous pleuritis even in HIV patients with very low CD4 counts in a high TB endemic region. The ADA assay is inexpensive, rapid, and simple to perform and is of great value for the immediate diagnosis of tuberculous pleuritis while waiting for culture result and this has a positive impact on patient outcome

Retinoid-independent motor neurogenesis from human embryonic stem cells reveals a medial columnar ground state

A major challenge in neurobiology is to understand mechanisms underlying human neuronal diversification. Motor neurons (MNs) represent a diverse collection of neuronal subtypes, displaying differential vulnerability in different human neurodegenerative diseases. The ability to manipulate cell subtype diversification is critical to establish accurate, clinically relevant in vitro disease models. Retinoid signalling contributes to caudal precursor specification and subsequent MN subtype diversification. Here we investigate the necessity for retinoic acid in motor neurogenesis from human embryonic stem cells. We show that activin/nodal signalling inhibition, followed by sonic hedgehog agonist treatment, is sufficient for MN precursor specification, which occurs even in the presence of retinoid pathway antagonists. Importantly, precursors mature into HB9/ChAT-expressing functional MNs. Furthermore, retinoid-independent motor neurogenesis results in a ground state biased to caudal, medial motor columnar identities from which a greater retinoid-dependent diversity of MNs, including those of lateral motor columns, can be selectively derived in vitro

Non-invasive ventilation in obesity hypoventilation syndrome without severe obstructive sleep apnoea

Background Non-invasive ventilation (NIV) is an effective form of treatment in patients with obesity hypoventilation syndrome (OHS) who have concomitant severe obstructive sleep apnoea (OSA). However, there is a paucity of evidence on the efficacy of NIV in patients with OHS without severe OSA. We performed a multicentre randomised clinical trial to determine the comparative efficacy of NIV versus lifestyle modification (control group) using daytime arterial carbon dioxide tension (PaCO2) as the main outcome measure. Methods Between May 2009 and December 2014 we sequentially screened patients with OHS without severe OSA. Participants were randomised to NIV versus lifestyle modification and were followed for 2 months. Arterial blood gas parameters, clinical symptoms, health-related quality of life assessments, polysomnography, spirometry, 6-min walk distance test, blood pressure measurements and healthcare resource utilisation were evaluated. Statistical analysis was performed using intention-to-treat analysis. Results A total of 365 patients were screened of whom 58 were excluded. Severe OSA was present in 221 and the remaining 86 patients without severe OSA were randomised. NIV led to a significantly larger improvement in PaCO2 of -6 (95% CI -7.7 to -4.2) mm Hg versus -2.8 (95% CI -4.3 to -1.3) mm Hg, (p<0.001) and serum bicarbonate of -3.4 (95% CI -4.5 to -2.3) versus -1 (95% CI -1.7 to -0.2 95% CI) mmol/L (p<0.001). PaCO2 change adjusted for NIV compliance did not further improve the inter-group statistical significance. Sleepiness, some health-related quality of life assessments and polysomnographic parameters improved significantly more with NIV than with lifestyle modification. Additionally, there was a tendency towards lower healthcare resource utilisation in the NIV group. Conclusions NIV is more effective than lifestyle modification in improving daytime PaCO2, sleepiness and polysomnographic parameters. Long-term prospective studies are necessary to determine whether NIV reduces healthcare resource utilisation, cardiovascular events and mortality

The intermediate polar cataclysmic variable GK Persei 120 years after the nova explosion: a first dynamical mass study

We present a dynamical study of the intermediate polar and dwarf nova cataclysmic variable GK Persei (Nova Persei 1901) based on a multisite optical spectroscopy and R-band photometry campaign. The radial velocity curve of the evolved donor star has a semi-amplitude K-2 = 126.4 +/- 0.9 km s(-1) and an orbital period P = 1.996872 +/- 0.000009 d. We refine the projected rotational velocity of the donor star to v(rot) sin i = 52 +/- 2 km s(-1) that, together with K-2, provides a donor star to white dwarf mass ratio q = M-2/M-1 = 0.38 +/- 0.03. We also determine the orbital inclination of the system by modelling the phase-folded ellipsoidal light curve and obtain i = 67 degrees +/- 5 degrees. The resulting dynamical masses are M-1 = 1.03(-0.11)(+0.16) M-circle dot and M-2 = 0.39(-0.06)(+0.07) M-circle dot at 68 per cent confidence level. The white dwarf dynamical mass is compared with estimates obtained by modelling the decline light curve of the 1901 nova event and X-ray spectroscopy. The best matching mass estimates come from the nova light curve models and an X-ray data analysis that uses the ratio between the Alfven radius in quiescence and during dwarf nova outburst

Beyond word frequency: Bursts, lulls, and scaling in the temporal distributions of words

Background: Zipf's discovery that word frequency distributions obey a power law established parallels between biological and physical processes, and language, laying the groundwork for a complex systems perspective on human communication. More recent research has also identified scaling regularities in the dynamics underlying the successive occurrences of events, suggesting the possibility of similar findings for language as well. Methodology/Principal Findings: By considering frequent words in USENET discussion groups and in disparate databases where the language has different levels of formality, here we show that the distributions of distances between successive occurrences of the same word display bursty deviations from a Poisson process and are well characterized by a stretched exponential (Weibull) scaling. The extent of this deviation depends strongly on semantic type -- a measure of the logicality of each word -- and less strongly on frequency. We develop a generative model of this behavior that fully determines the dynamics of word usage. Conclusions/Significance: Recurrence patterns of words are well described by a stretched exponential distribution of recurrence times, an empirical scaling that cannot be anticipated from Zipf's law. Because the use of words provides a uniquely precise and powerful lens on human thought and activity, our findings also have implications for other overt manifestations of collective human dynamics

Determinants of recovery from post-COVID-19 dyspnoea: analysis of UK prospective cohorts of hospitalised COVID-19 patients and community-based controls

BACKGROUND: The risk factors for recovery from COVID-19 dyspnoea are poorly understood. We investigated determinants of recovery from dyspnoea in adults with COVID-19 and compared these to determinants of recovery from non-COVID-19 dyspnoea. METHODS: We used data from two prospective cohort studies: PHOSP-COVID (patients hospitalised between March 2020 and April 2021 with COVID-19) and COVIDENCE UK (community cohort studied over the same time period). PHOSP-COVID data were collected during hospitalisation and at 5-month and 1-year follow-up visits. COVIDENCE UK data were obtained through baseline and monthly online questionnaires. Dyspnoea was measured in both cohorts with the Medical Research Council Dyspnoea Scale. We used multivariable logistic regression to identify determinants associated with a reduction in dyspnoea between 5-month and 1-year follow-up. FINDINGS: We included 990 PHOSP-COVID and 3309 COVIDENCE UK participants. We observed higher odds of improvement between 5-month and 1-year follow-up among PHOSP-COVID participants who were younger (odds ratio 1.02 per year, 95% CI 1.01–1.03), male (1.54, 1.16–2.04), neither obese nor severely obese (1.82, 1.06–3.13 and 4.19, 2.14–8.19, respectively), had no pre-existing anxiety or depression (1.56, 1.09–2.22) or cardiovascular disease (1.33, 1.00–1.79), and shorter hospital admission (1.01 per day, 1.00–1.02). Similar associations were found in those recovering from non-COVID-19 dyspnoea, excluding age (and length of hospital admission). INTERPRETATION: Factors associated with dyspnoea recovery at 1-year post-discharge among patients hospitalised with COVID-19 were similar to those among community controls without COVID-19. FUNDING: PHOSP-COVID is supported by a grant from the MRC-UK Research and Innovation and the Department of Health and Social Care through the National Institute for Health Research (NIHR) rapid response panel to tackle COVID-19. The views expressed in the publication are those of the author(s) and not necessarily those of the National Health Service (NHS), the NIHR or the Department of Health and Social Care. COVIDENCE UK is supported by the UK Research and Innovation, the National Institute for Health Research, and Barts Charity. The views expressed are those of the authors and not necessarily those of the funders