Zeeman Doppler Imaging of ksi Boo A and B

We present a magnetic-field surface map for both stellar components of the young visual binary ksi Boo AB (A: G8V, B: K5V). Employed are high resolution Stokes-V spectra obtained with the Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT). Stokes V line profiles are inverted with our iMAP software and compared to previous inversions. We employed an iterative regularization scheme without the need of a penalty function and incorporated a three-component description of the surface magnetic-field vector. The spectral resolution of our data is 130,000 (0.040-0.055A) and have signal-to-noise ratios (S/N) of up to three thousand per pixel depending on wavelength. A singular-value decomposition (SVD) of a total of 1811 spectral lines is employed for averaging Stokes-V profiles. Our mapping is accompanied by a residual bootstrap error analysis. Magnetic flux densities of the radial field component of up to plus/minus 115 +/- 5 G were reconstructed for ksi Boo A while up to plus/minus 55 +/- 3G were reconstructed for ksi Boo B. ksi Boo A's magnetic morphology is characterized by a very high latitude, nearly polar, spot of negative polarity and three low-to-mid latitude spots of positive polarity while ksi Boo B's morphology is characterized by four low-to-mid latitude spots of mixed polarity. No polar magnetic field is reconstructed for the cooler ksi Boo B star. Both our maps are dominated by the radial field component, containing 86 and 89 percent of the magnetic energy of ksi Boo A and B, respectively. We found only weak azimuthal and meridional field densities on both stars (plus/minus 15-30 G), about a factor two weaker than what was seen previously for ksi Boo A. The phase averaged longitudinal field component and dispersion is +4.5 +/- 1.5G for ksi Boo A and -5.0 +/- 3.0 G for ksi Boo B.Comment: 10 pages, 6 figures, accepted at A&A. arXiv admin note: text overlap with arXiv:1902.1120

Warm and cool starspots with opposite polarities. A high-resolution Zeeman-Doppler-Imaging study of II Pegasi with PEPSI

We present a temperature and a magnetic-field surface map of the K2 subgiant of the active binary II Peg. Employed are high resolution Stokes IV spectra obtained with the new Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT). Our main result is that the temperature features on II Peg closely correlate with its magnetic field topology. We find a warm spot (350K warmer with respect to the effective temperature) of positive polarity and radial field density of 1.1 kG coexisting with a cool spot (780K cooler) of negative polarity of 2 kG. Several other cool features are reconstructed containing both polarities and with (radial) field densities of up to 2 kG. The largest cool spot is reconstructed with a temperature contrast of 550 K, an area of almost 10% of the visible hemisphere, and with a multipolar magnetic morphology. A meridional and an azimuthal component of the field of up to +/-500G is detected in two surface regions between spots with strong radial fields but different polarities. A force-free magnetic-field extrapolation suggests that the different polarities of cool spots and the positive polarity of warm spots are physically related through a system of coronal loops of typical height of approx. 2 Rstar. While the H-alpha line core and its red-side wing exhibit variations throughout all rotational phases, a major increase of blue-shifted H-alpha emission was seen for the phases when the warm spot is approaching the stellar central meridian indicating high-velocity mass motion within its loop. We explain the warm spots due to photospheric heating by a shock front from a siphon-type flow between regions of different polarities while the majority of the cool spots is likely formed due to the expected convective suppression like on the Sun.Comment: 12 pages, 8 figure

On a "New" Deformation of GL(2)

We refute a recent claim in the literature of a "new" quantum deformation of GL(2).Comment: 4 pages, LATE

Doppler images and the underlying dynamo. The case of AF Leporis

The (Zeeman-)Doppler imaging studies of solar-type stars very often reveal large high-latitude spots. This also includes F stars that possess relatively shallow convection zones, indicating that the dynamo operating in these stars differs from the solar dynamo. We aim to determine whether mean-field dynamo models of late-F type dwarf stars can reproduce the surface features recovered in Doppler maps. In particular, we wish to test whether the models can reproduce the high-latitude spots observed on some F dwarfs. The photometric inversions and the surface temperature maps of AF Lep were obtained using the Occamian-approach inversion technique. Low signal-to-noise spectroscopic data were improved by applying the least-squares deconvolution method. The locations of strong magnetic flux in the stellar tachocline as well as the surface fields obtained from mean-field dynamo solutions were compared with the observed surface temperature maps. The photometric record of AF Lep reveals both long- and short-term variability. However, the current data set is too short for cycle-length estimates. From the photometry, we have determined the rotation period of the star to be 0.9660+-0.0023 days. The surface temperature maps show a dominant, but evolving, high-latitude (around +65 degrees) spot. Detailed study of the photometry reveals that sometimes the spot coverage varies only marginally over a long time, and at other times it varies rapidly. Of a suite of dynamo models, the model with a radiative interior rotating as fast as the convection zone at the equator delivered the highest compatibility with the obtained Doppler images.Comment: accepted for publication in Astronomy & Astrophysic

Mass of the higgs versus fourth generation masses

The predicted value of the higgs mass $m_H$ is analyzed assuming the existence of the fourth generation of leptons ($N, E$) and quarks ($U, D$). The steep and flat directions are found in the five-dimensional parameter space: $m_H$, $m_U$, $m_D$, $m_N$, $m_E$. The LEPTOP fit of the precision electroweak data is compatible (in particular) with $m_H \sim 300$ GeV, $m_N \sim 50$ GeV, $m_E \sim 100$ GeV, $m_U +m_D \sim 500$ GeV, and $|m_U -m_D| \sim 75$ GeV. The quality of fits drastically improves when the data on b- and c-quark asymmetries and new NuTeV data on deep inelastic scattering are ignored.Comment: 8 pages, 4 figure

The effect of protein mutations on drug binding suggests ensuing personalised drug selection

The advent of personalised medicine promises a deeper understanding of mechanisms and therefore therapies. However, the connection between genomic sequences and clinical treatments is often unclear. We studied 50 breast cancer patients belonging to a population-cohort in the state of Qatar. From Sanger sequencing, we identified several new deleterious mutations in the estrogen receptor 1 gene (ESR1). The effect of these mutations on drug treatment in the protein target encoded by ESR1, namely the estrogen receptor, was achieved via rapid and accurate protein-ligand binding affinity interaction studies which were performed for the selected drugs and the natural ligand estrogen. Four nonsynonymous mutations in the ligand-binding domain were subjected to molecular dynamics simulation using absolute and relative binding free energy methods, leading to the ranking of the efficacy of six selected drugs for patients with the mutations. Our study shows that a personalised clinical decision system can be created by integrating an individual patient's genomic data at the molecular level within a computational pipeline which ranks the efficacy of binding of particular drugs to variant proteins

ОСОБЛИВОСТІ ПСИХОФІЗІОЛОГІЧНОЇ ОРГАНІЗАЦІЇ СИСТЕМИ ПЕРЕРОБКИ ІНФОРМАЦІЇ У СПОРТСМЕНІВ РІЗНОЇ СТАТІ

The psychophysiological peculiarities of system of information processing in sportsmen of different sex were studied.Training in speed-strength sports (conventionally referred as “men’s sports”) causes changes in mental processes, namely in behaviour, character and emotional characteristics. Assuming that mental reactions during training and competitions determined mainly by changes in cognitive functions, we can hypothesize different structure of information processing system in men and women.The influence of sexual dimorphism on mental characteristics in elite athletes, 24 sportsmen (17 men and 7 women members of National Judo Team of Ukraine) has been determined.Obtained results confirmed significant difference of sexual dimorphism indices in athletes and sedentary people. It was determined the sexual dimorphism manifestations in athletes. Obtained results indicate influence of sexual dimorphism on psychophysiological functions.В работе представлены результаты исследований психофизиологических особенностей системы переработки информации у спортсменов разного пола.Исследовано проявление нейродинамических и когнитивных функций у 24 спортсменов, членов сборной команды Украины по дзюдо (17 мужчин и 7 женщин). Установлено, что проявления полового диморфизма у спортсменов и лиц, не занимающихся спортом, достоверно различаются. У спортсменов проявление полового диморфизма проявляется в наличии более высоких значений показателей когнитивных функций. Изучение системы переработки информации свидетельствует о наличии полового диморфизма при формировании различной организации психофизиологических функций.В роботі представлені результати досліджень психофізіологічних особливостей системи переробки інформації у спортсменів різної статі.Досліджено прояв нейродинамических і когнітивних функцій у 24 спортсменів, членів збірної команди України по дзюдо (17 чоловіків та 7 жінок). Встановлено, що прояви статевого диморфізму у спортсменів і осіб, які не займаються спортом, вірогідно розрізняються. У спортсменів прояв статевого диморфізму проявляється при наявності більш високих значень показників когнітивних функцій. Вивчення системи переробки інформації свідчить про наявність статевого диморфізму при формуванні різної організації психофізіологічних функцій