Context.
The characterization of the differential rotation of the extended corona is still lacking conclusive results about the actual rotation rate profiles, and it is also expected to vary along ...the solar cycle. While some studies supported the quasi-rigidity of coronal rotation, others have found evidence of differential rotation to occur.
Aims.
For the purpose of investigating the differential rotation of the solar corona, we analyzed ultraviolet (UV) spectral line observations acquired on both the east and west limbs at 1.7
R
⊙
by the Ultraviolet Coronagraph Spectrometer (UVCS) on-board the Solar and Heliospheric Observatory during the solar minimum preceding solar cycle 23. To obtain a reliable and statistically robust picture of the rotational profile, we used a set of simultaneous 400 day long spectral line intensities of five different spectral lines: O
VI
1032 Å, O
VI
1037 Å, Si
XII
499 Å, Si
XII
521 Å, and H
I
Ly
α
1216 Å, which are routinely observed by UVCS.
Methods.
The data were analyzed by means of two different techniques: the generalized Lomb-Scargle periodogram and a multivariate data-adaptive technique called multichannel singular spectrum analysis. Among many other positive outcomes, this latter method is unique in its ability to recognize common oscillatory modes between the five time series observed at both limbs.
Results.
The latitudinal rotation profile obtained in this work emphasizes that the low-latitude region of the UV corona (about ±20° from the solar equator) exhibits differential rotation, while the higher-latitude structures do rotate quasi-rigidly. Moreover, in contrast to previous results obtained using only O
VI
1032 Å data over a 365 day time interval during solar minimum activity, the alleged north-south rotational asymmetry of the UV corona, if existent, is much less pronounced.
Conclusions.
The differential rotation rate of the solar corona as evinced at low-latitudes is consistent with the rotational profile of the near-surface convective zone of the Sun, suggesting that the rotation of the corona at 1.7
R
⊙
is linked to intermediate-scale magnetic bipole structures anchored near 0.99
R
⊙
. The quasi-rigid rotation rate found at mid and high latitudes is instead attributed to the influence of large-scale coronal structures linked to the rigidly rotating coronal holes. We further suggest that the methodology presented in this paper could represent a milestone for future investigations on differential rotation rates when dealing with simultaneous multiwavelength data.
Full text
Available for:
FMFMET, NUK, UL, UM, UPUK
RDW is an erythrocyte index that increase in multiple myeloma, in which it appears to have an important role in predicting outcome. For this reason, we performed a retrospective analysis to evaluate ...the relationships of RDW with some important prognostic predictors. Specifically, in a cohort of 190 newly diagnosed multiple myeloma patients, we have examined the behaviour of RDW and its trend in relation to the ISS stage and other prognostic factors, such as albumin, beta-2 microglobulin, LDH and bone marrow plasma cell infiltration. We performed the analysis in the entire cohort of patients and in the three different disease isotypes (Light chain, IgA, and IgG multiple myeloma). The evaluation of RDW in the different isotypes was made with the Kruskal-Wallis test, integrated by the Dunn test. The comparison between the subgroups allocated above and below the median value of each prognostic factor, was made with the Mann-Whitney test. From our analysis, we observed that RDW is higher in the IgA multiple myeloma, and it increases significantly from ISS I to III. Moreover, RDW increases in the presence of lower albumin values, higher levels of beta2-microglobulin and LDH and in the presence of a greater bone marrow plasma cell infiltrate.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We report the detection of multiple quasi-periodic pulsations (QPPs) observed during the flaring activity of KIC 8414845, a young, active solar-type star observed by the
Kepler
mission launched by ...NASA. We analyzed the QQP signal using a data-driven, nonparametric method called singular spectrum analysis (SSA), which has never been utilized previously for analyzing solar or stellar QPPs. Because it is not based on a prescribed choice of basis functions, SSA is particularly suitable for analyzing nonstationary, nonlinear signals such as those observed in QPPs during major flares. The analysis has revealed that the apparent anharmonic shape of the QPP in this superflare results from a superposition of two intrinsic modes of periods of 49 min and 86 min, which display quasi-harmonic behaviors and different modulation patterns. The two reconstructed signals are consistent with slow-mode transverse and/or longitudinal magnetohydrodynamic oscillations excited in a coronal loop inducing periodic releases of flaring energy in a nearby loop through a mechanism of repetitive reconnection. The peculiar amplitude modulation of the two modes evinced by SSA favors the interpretation of the observed QPP pattern as due to the excitation in a coronal loop of the second harmonic of a standing slow-mode magnetoacoustic oscillation and a global kink oscillation periodically triggering magnetic reconnection in a nearby loop. Concurrent interpretations cannot however be ruled out on the basis of the available data.
Full text
Available for:
FMFMET, NUK, UL, UM, UPUK
We report on the study of a fast coronal mass ejection (CME)-driven shock associated with the solar eruption of 2002 March 22. This event was observed in the intermediate corona both in white light ...and the extreme ultraviolet (EUV) by the LASCO and UVCS instruments on board the Solar and Heliospheric Observatory, as well as in metric and decametric wavelengths through space- and ground-based radio observatories. Clear signatures of shock transit are (1) strong type II emission lanes observed after the CME initiation, (2) strong O VI {lambda}{lambda}1032, 1037 line profile broadenings (up to {approx}2 x 10{sup 7} K) associated with the shock transit across the UVCS slit field of view, and (3) a density enhancement located in LASCO images above the CME front. Since the UVCS slit was centered at 4.1 R{sub sun}, in correspondence with the flank of the expanding CME, this observation represents the highest UV detection of a shock obtained so far with the UVCS instrument. White-light and EUV data have been combined in order to estimate not only the shock compression ratio and the plasma temperature, but also the strength of the involved coronal magnetic fields, by applying the Rankine-Hugoniot equations for the general case of oblique shocks. Results show that, for a compression ratio X = 2.06 as derived from LASCO data, the coronal plasma is heated across the shock from an initial temperature of 2.3 x 10{sup 5} K up to 1.9 x 10{sup 6} K, while at the same time the magnetic field undergoes a compression from a pre-shock value of {approx}0.02 G up to a post-shock field of {approx}0.04 G. Magnetic and kinetic energy density increases at the shock are comparable (in agreement with the idea of equipartition of energy), and both are more than two times larger than the thermal energy density increase. This is the first time that a complete characterization of pre- and post-shock plasma physical parameters has been derived in the solar corona.
•HPLC and PTR-TOF-MS combined approach for the study of saffron (Crocus sativus L.) with different geographic origins.•The combination of the two techniques allows a better characterization of ...saffron of different geographic areas.•Safranal, isophorone and picrocrocin turn out to be the most significant compounds for saffron characterization.
Saffron samples from Italy and Iran were analyzed for their content in aroma and bioactive compounds with different analytical techniques. HPLC was used for the identification and quantification of crocins, picrocrocin, safranal and flavonoids content, while the novel proton transfer reaction time-of-flight mass spectrometer was employed for the aroma compounds analysis. Italian saffron turned out to be richer in total crocins and safranal contents. Sample characterization was performed with an unsupervised statistical approach; tests involving different numbers of parameters deriving from the two analytical techniques were performed. The results achieved showed that the best samples classification was obtained by joining the information acquired from both techniques; following such an approach, a sharper separation between Iranian and Italian samples was achieved. Finally, among the variables that most contribute to the description of variability, isophorone, safranal and picrocrocin were identified to be the most significant.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Objective We sought to identify risk factors for uterine atony or hemorrhage. Study Design We conducted a secondary analysis of a 3-arm double-blind randomized trial of different dose regimens of ...oxytocin to prevent uterine atony after vaginal delivery. The primary outcome was uterine atony or hemorrhage requiring treatment. In all, 21 potential risk factors were evaluated. Logistic regression was used to identify independent risk factors using 2 complementary predefined model selection strategies. Results Among 1798 women randomized to 10, 40, or 80 U of prophylactic oxytocin after vaginal delivery, treated uterine atony occurred in 7%. Hispanic (odds ratio OR, 2.1; 95% confidence interval CI, 1.3–3.4), non-Hispanic white (OR, 1.6; 95% CI, 1.0–2.5), preeclampsia (OR, 3.2; 95% CI, 2.0–4.9), and chorioamnionitis (OR, 2.8; 95% CI, 1.6–5.0) were consistent independent risk factors. Other risk factors based on the specified selection strategies were obesity, induction/augmentation of labor, twins, hydramnios, anemia, and arrest of descent. Amnioinfusion appeared to be protective against uterine atony (OR, 0.53; 95% CI, 0.29–0.98). Conclusion Independent risk factors for uterine atony requiring treatment include Hispanic and non-Hispanic white ethnicity, preeclampsia, and chorioamnionitis.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Aim
There is a paucity of data on the clinical presentation and management of cancer patients with acquired haemophilia (AH), we here report a systematic literature review on acquired haemophilia in ...the context of cancer.
Methods
Treatment outcomes of AH were defined as complete response (CR), partial response (PR) or no response (NR), based on inhibitor eradication, coagulation factor VIII levels and bleeding control. Reported deaths were either related to cancer or bleeding.
Results
Overall, 105 cases were collected and analyzed according to classification of cancer and efficacy of treatments for inhibitor and malignancy. The mean age was 68 years for both males (range 37‐86 years) and females (range 43‐89 years), 39 patients were female subjects and 66 were males. A solid cancer was diagnosed in 60 subjects, while 45 patients suffered a haematological malignancy. Solid cancers affected mainly males; however, the incidence of solid tumours vs haematological malignancies was not statistically significant (P = .09). Not all patients were treated for their underlying cancer, bleeding and/or inhibitor, in two cases outcome is unavailable. CR was reported in 62.1% (64/103) cases, PR in 9.7% (10/103) cases, NR with or without death was reported in 28.1% (29/103) cases.
Conclusion
CR was best achieved when successful and complete elimination of autoantibodies occurred contemporaneously with the successful treatment of the underlying malignancy. In some cases, recurrent autoantibodies were harbingers of relapsed cancer. Type of cancer, inhibitor titer, treatments administered for bleeding control and inhibitor eradication did not significantly affect clinical outcome of analyzed cases.
Full text
Available for:
DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
ABSTRACT
Predicting the solar activity of upcoming cycles is crucial nowadays to anticipate potentially adverse space weather effects on the Earth’s environment produced by coronal transients and ...traveling interplanetary disturbances. The latest advances in deep learning techniques provide new paradigms to obtain effective prediction models that allow to forecast in detail the evolution of cosmogeophysical time series. Because of the underlying complexity of the dynamo mechanism in the solar interior that is at the origin of the solar cycle phenomenon, the predictions offered by state-of-the-art machine learning algorithms represent valuable tools for our understanding of the cycle progression. As a plus, Bayesian deep learning is particularly compelling thanks to recent advances in the field that provide improvements in both accuracy and uncertainty quantification compared to classical techniques. In this work, a deep learning long short-term memory model is employed to predict the complete profile of Solar Cycle 25, thus forecasting also the advent of the next solar minimum. A rigorous uncertainty estimation of the predicted sunspot number is obtained by applying a Bayesian approach. Two different model validation techniques, namely the Train-Test split and the time series k-fold cross-validation, have been implemented and compared, giving compatible results. The forecasted peak amplitude is lower than that of the preceding cycle. Solar Cycle 25 will last 10.6 ± 0.7 yr, reaching its maximum in the middle of the year 2024. The next solar minimum is predicted in 2030 and will be as deep as the previous one.
ABSTRACT We report here on the determination of plasma physical parameters across a shock driven by a coronal mass ejection using white light (WL) coronagraphic images and radio dynamic spectra ...(RDS). The event analyzed here is the spectacular eruption that occurred on 2011 June 7, a fast CME followed by the ejection of columns of chromospheric plasma, part of them falling back to the solar surface, associated with a M2.5 flare and a type-II radio burst. Images acquired by the Solar and Heliospheric Observatory/LASCO coronagraphs (C2 and C3) were employed to track the CME-driven shock in the corona between 2-12 R in an angular interval of about 110°. In this interval we derived two-dimensional (2D) maps of electron density, shock velocity, and shock compression ratio, and we measured the shock inclination angle with respect to the radial direction. Under plausible assumptions, these quantities were used to infer 2D maps of shock Mach number MA and strength of coronal magnetic fields at the shock's heights. We found that in the early phases (2-4 R ) the whole shock surface is super-Alfvénic, while later on (i.e., higher up) it becomes super-Alfvénic only at the nose. This is in agreement with the location for the source of the observed type-II burst, as inferred from RDS combined with the shock kinematic and coronal densities derived from WL. For the first time, a coronal shock is used to derive a 2D map of the coronal magnetic field strength over intervals of 10 R altitude and ∼110° latitude.
Abstract
Background and Aims
Anaesthesia for medical purposes was introduced in the 19th century. However, the physiological mode of anaesthetic drug actions on the nervous system remains unclear. ...One of the remaining questions is how these different compounds, with no structural similarities and even chemically inert elements such as the noble gas xenon, act as anaesthetic agents inducing loss of consciousness. The main goal here was to determine if anaesthetics affect the same or similar processes in plants as in animals and humans.
Methods
A single-lens reflex camera was used to follow organ movements in plants before, during and after recovery from exposure to diverse anaesthetics. Confocal microscopy was used to analyse endocytic vesicle trafficking. Electrical signals were recorded using a surface AgCl electrode.
Key Results
Mimosa leaves, pea tendrils, Venus flytraps and sundew traps all lost both their autonomous and touch-induced movements after exposure to anaesthetics. In Venus flytrap, this was shown to be due to the loss of action potentials under diethyl ether anaesthesia. The same concentration of diethyl ether immobilized pea tendrils. Anaesthetics also impeded seed germination and chlorophyll accumulation in cress seedlings. Endocytic vesicle recycling and reactive oxygen species (ROS) balance, as observed in intact Arabidopsis root apex cells, were also affected by all anaesthetics tested.
Conclusions
Plants are sensitive to several anaesthetics that have no structural similarities. As in animals and humans, anaesthetics used at appropriate concentrations block action potentials and immobilize organs via effects on action potentials, endocytic vesicle recycling and ROS homeostasis. Plants emerge as ideal model objects to study general questions related to anaesthesia, as well as to serve as a suitable test system for human anaesthesia.
Full text
Available for:
IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
PDF
