Non-adiabatic magnetohydrodynamic waves in a cylindrical prominence thread with mass flow

High-resolution observations show that oscillations and waves in prominence threads are common and that they are attenuated in a few periods. In addition, observers have also reported the presence of material flows in such prominence fine-structures. Here we investigate the time damping of non-leaky oscillations supported by a homogeneous cylindrical prominence thread embedded in an unbounded corona and with a steady mass flow. Thermal conduction and radiative losses are taken into account as damping mechanisms, and the effect of these non-ideal effects and the steady flow on the attenuation of oscillations is assessed. We solve the general dispersion relation for linear, non-adiabatic magnetoacoustic and thermal waves supported by the model, and find that slow and thermal modes are efficiently attenuated by non-adiabatic mechanisms. On the contrary, fast kink modes are much less affected and their damping times are much larger than those observed. The presence of flow has no effect on the damping of slow and thermal waves, whereas fast kink waves are more (less) attenuated when they propagate parallel (anti-parallel) to the flow direction. Although the presence of steady mass flows improves the efficiency of non-adiabatic mechanisms on the attenuation of transverse, kink oscillations for parallel propagation to the flow, its effect is still not enough to obtain damping times compatible with observations.Comment: Accepted for publication in Ap

For Psyche

In the present study we investigated peroxisomal functions in cultured human muscle cells from control subjects and from a patient with the Zellweger syndrome, a genetic disease characterized by the absence of morphologically distinguishable peroxisomes in liver and kidney. In homogenates of cultured muscle cells from control subjects, catalase is contained within subcellular particles, acyl-CoA:dihydroxyacetonephosphate acyltransferase activity is present and palmitoyl-CoA can be oxidized by a peroxisomal beta-oxidative pathway; these findings are indicative of the presence of peroxisomes in the cells. In homogenates of cultured muscle cells from the patient with the Zellweger syndrome, acyl-CoA:dihydroxyacetonephosphate acyltransferase activity was deficient, peroxisomal beta-oxidation of palmitoyl-CoA was impaired and catalase was not particle-bound. These findings indicate that functional peroxisomes are absent in muscle from patients with the Zellweger syndrome. We conclude that cultured human muscle cells can be used as a model system to study peroxisomal functions in muscle and the consequences for this tissue of a generalized dysfunction of peroxisome

High prevalence of heavy menstrual bleeding in women with rare bleeding disorders in the Netherlands:retrospective data from the RBiN study

Background: Heavy menstrual bleeding (HMB) is associated with a reduced quality of life and limitations in social and physical functioning. Data on HMB in women with rare bleeding disorders (RBDs), including coagulation factor deficiencies and fibrinolytic disorders, are scarce. Objectives: To analyze the prevalence, severity, and treatment of HMB in Dutch women with an RBD. Methods:The Rare Bleeding Disorders in the Netherlands (RBiN) study included 263 patients with an RBD from all 6 hemophilia treatment centers (October 2017-November 2019). In this analysis, data of 111 women aged ≥16 years were studied. According to the International Society on Thrombosis and Haemostasis bleeding assessment tool, HMB symptoms were scored from 0 (no/trivial) to 4 (severe symptoms requiring medical intervention). HMB was defined as a score ≥1. Age at RBD diagnosis was extracted from patient files. Results: HMB was reported by 80% of women (89/111) and was more prevalent in women with a fibrinolytic disorder (33/35; 94%) than in women with a coagulation factor deficiency (56/76; 74%) (P = .011). Of the 89 women with HMB, 82% (n = 73) ever required treatment. Multiple treatment modalities were frequently used, both in severe and mild deficiencies. Hormonal treatment was mostly used (n = 64; 88%), while antifibrinolytics were prescribed less frequently (n = 18; 25%). In women with HMB since menarche (n = 61; 69%), median age at RBD diagnosis was 28 years (IQR, 14-41).Conclusion: HMB is common in women with RBDs. Women with mild deficiencies also frequently reported HMB. Only a minority of women were treated with hemostatic agents. A significant diagnostic delay was observed after the onset of HMB symptoms.</p

Prominence seismology using small amplitude oscillations

Quiescent prominences are thin slabs of cold, dense plasma embedded in the much hotter and rarer solar corona. Although their global shape is rather irregular, they are often characterised by an internal structure consisting of a large number of thin, parallel threads piled together. Prominences often display periodic disturbances mostly observed in the Doppler displacement of spectral lines and with an amplitude typically of the order of or smaller than 2--3 km s$^{-1}$, a value which seems to be much smaller than the characteristic speeds of the prominence plasma (namely the Alfv\'en and sound velocities). Two particular features of these small amplitude prominence oscillations is that they seem to damp in a few periods and that they seem not to affect the whole prominence structure. In addition, in high spatial resolution observations, in which threads can be discerned, small amplitude oscillations appear to be clearly associated to these fine structure constituents. Prominence seismology tries to bring together the results from these observations (e.g. periods, wavelengths, damping times) and their theoretical modeling (by means of the magnetohydrodynamic theory) to gain insight into physical properties of prominences that cannot be derived from direct observation. In this paper we discuss works that have not been described in previous reviews, namely the first seismological application to solar prominences and theoretical advances on the attenuation of prominence oscillations

An AeroCom–AeroSat study: intercomparison of satellite AOD datasets for aerosol model evaluation

To better understand and characterize current uncertainties in the important observational constraint of climate models of aerosol optical depth (AOD), we evaluate and intercompare 14 satellite products, representing nine different retrieval algorithm families using observations from five different sensors on six different platforms. The satellite products (super-observations consisting of 1 degrees x 1 degrees daily aggregated retrievals drawn from the years 2006, 2008 and 2010) are evaluated with AErosol RObotic NETwork (AERONET) and Maritime Aerosol Network (MAN) data. Results show that different products exhibit different regionally varying biases (both under- and overestimates) that may reach +/- 50 %, although a typical bias would be 15 %-25 % (depending on the product). In addition to these biases, the products exhibit random errors that can be 1.6 to 3 times as large. Most products show similar performance, although there are a few exceptions with either larger biases or larger random errors. The intercomparison of satellite products extends this analysis and provides spatial context to it. In particular, we show that aggregated satellite AOD agrees much better than the spatial coverage (often driven by cloud masks) within the 1 degrees x 1 degrees grid cells. Up to similar to 50 % of the difference between satellite AOD is attributed to cloud contamination. The diversity in AOD products shows clear spatial patterns and varies from 10 % (parts of the ocean) to 100 % (central Asia and Australia). More importantly, we show that the diversity may be used as an indication of AOD uncertainty, at least for the better performing products. This provides modellers with a global map of expected AOD uncertainty in satellite products, allows assessment of products away from AERONET sites, can provide guidance for future AERONET locations and offers suggestions for product improvements. We account for statistical and sampling noise in our analyses. Sampling noise, variations due to the evaluation of different subsets of the data, causes important changes in error metrics. The consequences of this noise term for product evaluation are discussed

Advantages of the nested case-control design in diagnostic research

Abstract Background Despite its benefits, it is uncommon to apply the nested case-control design in diagnostic research. We aim to show advantages of this design for diagnostic accuracy studies. Methods We used data from a full cross-sectional diagnostic study comprising a cohort of 1295 consecutive patients who were selected on their suspicion of having deep vein thrombosis (DVT). We draw nested case-control samples from the full study population with case:control ratios of 1:1, 1:2, 1:3 and 1:4 (per ratio 100 samples were taken). We calculated diagnostic accuracy estimates for two tests that are used to detect DVT in clinical practice. Results Estimates of diagnostic accuracy in the nested case-control samples were very similar to those in the full study population. For example, for each case:control ratio, the positive predictive value of the D-dimer test was 0.30 in the full study population and 0.30 in the nested case-control samples (median of the 100 samples). As expected, variability of the estimates decreased with increasing sample size. Conclusion Our findings support the view that the nested case-control study is a valid and efficient design for diagnostic studies and should also be (re)appraised in current guidelines on diagnostic accuracy research.</p

Maternal and neonatal bleeding complications in relation to peripartum management in hemophilia carriers:A systematic review

Currently, there is no consensus on the optimal management to prevent postpartum hemorrhage (PPH) in hemophilia carriers. We aimed to evaluate peripartum management strategies in relation to maternal and neonatal bleeding outcomes by performing an extensive database search up to August 2020. Seventeen case-reports/series and 11 cohort studies were identified of overall 'poor' quality describing 502 deliveries. The PPH incidence in the individual patient data was 63%; 44% for those women receiving prophylaxis to correct coagulation and 77% for those without (OR 0.23, CI 0.09-0.58) and in cohort data 20.3% (26.8% (11/41) vs. 19.4% (55/284) (OR: 1.53, 95% CI: 0.72-3.24), respectively. Peripartum management strategies mostly consisted of clotting factor concentrates, rarely of desmopressin or plasma. Tranexamic acid appears promising in preventing secondary PPH, but was not used consistently. Neonatal bleeding was described in 6 affected male neonates, mostly after instrumental delivery or emergency CS, but insufficient information was provided to reliably investigate neonatal outcome in relation to management. The high PPH risk seems apparent, at most mildly attenuated by prophylactic treatment. Prospective cohort studies are needed to determine the optimal perinatal management in hemophilia.Thrombosis and Hemostasi

Flow cytometric mepacrine fluorescence can be used for the exclusion of platelet dense granule deficiency

Background: δ-storage pool disease (δ-SPD) is a bleeding disorder characterized by a reduced number of platelet-d