Effect of demographic features on morphometric variables of the knee joint: Sample of a 20 to 40-year-old Turkish population

This study aimed to investigate the relationship between body mass index (BMI), age, and sex and morphological risk factors that may cause internal knee injuries. The magnetic resonance images of 728 participants who met the inclusion criteria and had a mean age of 34.4?±?6.8 years were analyzed retrospectively. Demographic differences were analyzed by measuring 17 morphological parameters known to be associated with internal knee injuries. Men had a higher anterior cruciate ligament length (ACLL), anterior cruciate ligament width, (ACLW) lateral femoral condylar width (LFCW), medial femoral condylar width (MFCW), lateral femoral condylar depth (LFCD), distal femoral width (DFW), and intercondylar femoral width (IFW) than women (P?<?.05). By contrast, the medial meniscus bone angle (MMBA) was lower in men than in women (P?<?.05). Women aged 31 to 40 years had a lower Insall-Salvati index (ISI) and lateral tibial posterior slope (LTPS) than those aged 21 to 30 years (P?<?.05), whereas men aged 31 to 40 years had a lower ISI than those aged 21 to 30 years (P?<?.05). Women with BMI???30 had a higher LFCW and MFCW but a lower ISI than those with BMI?<?30 (P?<?.05). Men with BMI???30 had a higher LFCW, MFCW, DFW, and MMBA than those with BMI?<?30 (P?<?.05). The use of value ranges structured according to demographic characteristics, rather than a single value range for all patient groups, may contribute to the evaluation and treatment of the morphological features that are thought to be effective in the development of internal knee injuries. These values may also shed light on future radiological risk scoring systems and artificial intelligence applications in medicine. Copyright © 2023 the Author(s). Published by Wolters Kluwer Health, Inc

A Distinctive Disk-Jet Coupling in the Seyfert-1 AGN NGC 4051

We report on the results of a simultaneous monitoring campaign employing eight Chandra X-ray (0.5-10 keV) and six VLA/EVLA (8.4 GHz) radio observations of NGC 4051 over seven months. Evidence for compact jets is observed in the 8.4 GHz radio band; This builds on mounting evidence that jet production may be prevalent even in radio-quiet Seyferts. Assuming comparatively negligible local diffuse emission in the nucleus, the results also demonstrate an inverse correlation of L_radio proportional to L_X-ray ^(-0.72+/-0.04) . Current research linking the mass of supermassive black holes and stellar-mass black holes in the "low/hard" state to X-ray luminosities and radio luminosities suggest a "fundamental plane of accretion onto black holes" that has a positive correlation of L_radio proportional to L_X-ray^(0.67+/-0.12) . Our simultaneous results differ from this relation by more than 11 sigma, indicating that a separate mode of accretion and ejection may operate in this system. A review of the literature shows that the inverse correlation seen in NGC 4051 is seen in three other black hole systems, all of which accrete at near 10% of their Eddington luminosity, perhaps suggesting a distinct mode of disk-jet coupling at high Eddington fractions. We discuss our results in the context of disk and jets in black holes and accretion across the black hole mass scale.Comment: 12 pages, 9 figure

Illness tracking in SARS-CoV-2 tested persons using a smartphone app: a non-interventional, prospective, cohort study

There are few data on the range and severity of symptoms of SARS-CoV-2 infection or the impact on life quality in infected, previously healthy, young adults such as Swiss Armed Forces personnel. It is also unclear if an app can be used to remotely monitor symptoms in persons who test positive. Using a smartphone app called ITITP (Illness Tracking in Tested Persons) and weekly pop-up questionnaires, we aimed to evaluate the spectrum, duration, and impact of symptoms reported after a positive SARS-CoV-2 test according to sex, age, location, and comorbidities, and to compare these to responses from persons who tested negative. We followed up 502 participants (57% active participation), including 68 (13.5%) positive tested persons. Hospitalisation was reported by 6% of the positive tested participants. We found that positives reported significantly more symptoms that are typical of COVID-19 compared to negatives. These symptoms with odds ratio (OR > 1) were having difficulty breathing (OR 3.35; 95% CI: 1.16, 9.65; p = 0.03), having a reduced sense of taste (OR 5.45; 95% CI: 1.22, 24.34; p = 0.03) and a reduced sense of smell (OR 18.24; 95% CI: 4.23, 78.69; p < 0.001). Using a random forest model, we showed that tiredness was the single symptom that was rated as having a significant impact on daily activities, whereas the other symptoms, although frequent, had less impact. The study showed that the use of an app was feasible to remotely monitor symptoms in persons infected with SARS-CoV-2 and could be adapted for other settings and new pandemic phases such as the current Omicron wave

Supermassive black holes do not correlate with dark matter halos of galaxies

Supermassive black holes have been detected in all galaxies that contain bulge components when the galaxies observed were close enough so that the searches were feasible. Together with the observation that bigger black holes live in bigger bulges, this has led to the belief that black hole growth and bulge formation regulate each other. That is, black holes and bulges "coevolve". Therefore, reports of a similar correlation between black holes and the dark matter halos in which visible galaxies are embedded have profound implications. Dark matter is likely to be nonbaryonic, so these reports suggest that unknown, exotic physics controls black hole growth. Here we show - based in part on recent measurements of bulgeless galaxies - that there is almost no correlation between dark matter and parameters that measure black holes unless the galaxy also contains a bulge. We conclude that black holes do not correlate directly with dark matter. They do not correlate with galaxy disks, either. Therefore black holes coevolve only with bulges. This simplifies the puzzle of their coevolution by focusing attention on purely baryonic processes in the galaxy mergers that make bulges.Comment: 12 pages, 9 Postscript figures, 1 table; published in Nature (20 January 2011

Physics of the Galactic Center Cloud G2, on its Way towards the Super-Massive Black Hole

The origin, structure and evolution of the small gas cloud, G2, is investigated, that is on an orbit almost straight into the Galactic central supermassive black hole (SMBH). G2 is a sensitive probe of the hot accretion zone of Sgr A*, requiring gas temperatures and densities that agree well with models of captured shock-heated stellar winds. Its mass is equal to the critical mass below which cold clumps would be destroyed quickly by evaporation. Its mass is also constrained by the fact that at apocenter its sound crossing timescale was equal to its orbital timescale. Our numerical simulations show that the observed structure and evolution of G2 can be well reproduced if it formed in pressure equilibrium with the surrounding in 1995 at a distance from the SMBH of 7.6e16 cm. If the cloud would have formed at apocenter in the 'clockwise' stellar disk as expected from its orbit, it would be torn into a very elongated spaghetti-like filament by 2011 which is not observed. This problem can be solved if G2 is the head of a larger, shell-like structure that formed at apocenter. Our numerical simulations show that this scenario explains not only G2's observed kinematical and geometrical properties but also the Br_gamma observations of a low surface brightness gas tail that trails the cloud. In 2013, while passing the SMBH G2 will break up into a string of droplets that within the next 30 years mix with the surrounding hot gas and trigger cycles of AGN activity.Comment: 22 pages, 13 figures, submitted to Ap

Regulation of Black Hole Winds and Jets across the Mass Scale

We present a study of the mechanical power generated by both winds and jets across the black hole mass scale. We begin with the study of ionized X-ray winds and present a uniform analysis using Chandra grating spectra. The high-quality grating spectra facilitate the characterization of the outflow velocity, ionization, and column density of the absorbing gas. We find that the kinetic power of the winds, derived from these observed quantities, scales with increasing bolometric luminosity as log (L wind, 42/Cv ) = (1.58 ± 0.07)log (L Bol, 42) - (3.19 ± 0.19). This suggests that supermassive black holes may be more efficient than stellar-mass black holes in launching winds, per unit filling factor, Cv . If the black hole binary (BHB) and active galactic nucleus (AGN) samples are fit individually, the slopes flatten to αBHB = 0.91 ± 0.31 and αAGN = 0.63 ± 0.30 (formally consistent within errors). The broad fit and individual fits both characterize the data fairly well, and the possibility of common slopes may point to common driving mechanisms across the mass scale. For comparison, we examine jet production, estimating jet power based on the energy required to inflate local bubbles. The jet relation is log (L Jet, 42) = (1.18 ± 0.24)log (L Bondi, 42) - (0.96 ± 0.43). The energetics of the bubble associated with Cygnus X-1 are particularly difficult to determine, and the bubble could be a background supernova remnant. If we exclude Cygnus X-1 from our fits, then the jets follow a relation consistent with the winds, but with a higher intercept, log (L Jet, 42) = (1.34 ± 0.50)log (L Bondi, 42) - (0.80 ± 0.82). The formal consistency in the wind and jet scaling relations, when assuming that L Bol and L Bondi are both proxies for mass accretion rate, suggests that a common launching mechanism may drive both flows; magnetic processes, such as magnetohydrodynamics and magnetocentrifugal forces, are viable possibilities. We also examine winds that are moving at especially high velocities, v \u3e 0.01c. These ultra-fast outflows tend to resemble the jets more than the winds in terms of outflow power, indicating that we may be observing a regime in which winds become jets. A transition at approximately L Bol ≈ 10-2 L Edd is apparent when outflow power is plotted versus Eddington fraction. At low Eddington fractions, the jet power is dominant, and at high Eddington fractions, the wind power is dominant. This study allows for the total power from black hole accretion, both mechanical and radiative, to be characterized in a simple manner and suggests possible connections between winds and jets. X-ray wind data and jet cavity data will enable stronger tests

Constraints on the faint end of the quasar luminosity function at z~5 in the COSMOS field

We present the result of our low-luminosity quasar survey in the redshift range of 4.5 < z < 5.5 in the COSMOS field. Using the COSMOS photometric catalog, we selected 15 quasar candidates with 22 < i' < 24 at z~5, that are ~ 3 mag fainter than the SDSS quasars in the same redshift range. We obtained optical spectra for 14 of the 15 candidates using FOCAS on the Subaru Telescope and did not identify any low-luminosity type-1 quasars at z~5 while a low-luminosity type-2 quasar at z~5.07 was discovered. In order to constrain the faint end of the quasar luminosity function at z~5, we calculated the 1sigma confidence upper limits of the space density of type-1 quasars. As a result, the 1sigma confidence upper limits on the quasar space density are Phi< 1.33*10^{-7} Mpc^{-3} mag^{-1} for -24.52 < M_{1450} < -23.52 and Phi< 2.88*10^{-7} Mpc^{-3} mag^{-1} for -23.52 < M_{1450} < -22.52. The inferred 1sigma confidence upper limits of the space density are then used to provide constrains on the faint-end slope and the break absolute magnitude of the quasar luminosity function at z~5. We find that the quasar space density decreases gradually as a function of redshift at low luminosity (M_{1450} ~ -23), being similar to the trend found for quasars with high luminosity (M_{1450}<-26). This result is consistent with the so-called downsizing evolution of quasars seen at lower redshifts.Comment: 8 pages, 9 figures, 1 table, accepted for publication in Ap

Regulation of Black Hole Winds and Jets Across the Mass Scale

We present a study of the mechanical power generated by both winds and jets across the black hole mass scale. We begin with the study of ionized X-ray winds and present a uniform analysis using Chandra grating spectra. The high quality grating spectra facilitate the characterization of the outflow velocity, ionization and column density of the absorbing gas. We find that the kinetic power of the winds scales with increasing bolometric luminosity as log(L_wind) \propto (1.58 \pm 0.07) log(L_Bol). This means that SMBH may be more efficient than stellar-mass black holes in launching winds. In addition, the simplicity of the scaling may suggest common driving mechanisms across the mass scale. For comparison, we next examine jet production, estimating jet power based on the energy required to inflate local bubbles. The jet relation is log(L_Jet)\propto (1.18\pm0.24) log(L_Bol). The energetics of the bubble associated with Cygnus X-1 are particularly difficult to determine, and the bubble could be a background SNR. If we exclude Cygnus X-1, then the jets follow a consistent relation to the winds within errors but with a higher normalization, log(L_Jet) \propto (1.34 \pm 0.50) log(L_Bol). The formal consistency in the wind and jet scaling relations suggests that a common launching mechanism may drive both flows; magnetic processes are viable possibilities. We also examine winds with especially high velocities, v > 0.01c. These ultra-fast outflows tend to resemble the jets more than the winds, indicating we may be observing a regime in which winds become jets. This study allows for the total power from black hole accretion, both mechanical and radiative, to be characterized in a simple manner and suggests a possible connection between winds and jets. Finally, we find at low Eddington fractions, the jet power is dominant, and at high Eddington fractions the wind power is dominant.Comment: 24 pages, 10 figures, Accepted to ApJ on 16 Nov 201