On eigenvectors of nilpotent Lie algebras of linear operators

We give a condition ensuring that the operators in a nilpotent Lie algebra of linear operators on a finite dimensional vector space have a common eigenvector.Comment: Four page

Microscopic mass estimations

The quest to build a mass formula which have in it the most relevant microscopic contributions is analyzed. Inspired in the successful Duflo-Zuker mass description, the challenges to describe the shell closures in a more transparent but equally powerful formalism are discussed.Comment: 14 pages, 6 figures, submitted to Journal of Physics G, Focus issue on Open Problems in Nuclear Structure Theor

Structural Analysis of the Voltage-Dependent Calcium Channel β Subunit Functional Core and Its Complex with the α1 Interaction Domain

AbstractVoltage-dependent calcium channels (VDCC) are multiprotein assemblies that regulate the entry of extracellular calcium into electrically excitable cells and serve as signal transduction centers. The α1 subunit forms the membrane pore while the intracellular β subunit is responsible for trafficking of the channel to the plasma membrane and modulation of its electrophysiological properties. Crystallographic analyses of a β subunit functional core alone and in complex with a α1 interaction domain (AID) peptide, the primary binding site of β to the α1 subunit, reveal that β represents a novel member of the MAGUK protein family. The findings illustrate how the guanylate kinase fold has been fashioned into a protein-protein interaction module by alteration of one of its substrate sites. Combined results indicate that the AID peptide undergoes a helical transition in binding to β. We outline the mechanistic implications for understanding the β subunit's broad regulatory role of the VDCC, particularly via the AID

HAT-P-11: Discovery of a Second Planet and a Clue to Understanding Exoplanet Obliquities

HAT-P-11 is a mid-K dwarf that hosts one of the first Neptune-sized planets found outside the solar system. The orbit of HAT-P-11b is misaligned with the star's spin --- one of the few known cases of a misaligned planet orbiting a star less massive than the Sun. We find an additional planet in the system based on a decade of precision radial velocity (RV) measurements from Keck/HIRES. HAT-P-11c is similar to Jupiter in its mass ($M_P \sin{i} = 1.6\pm0.1$ $M_J$) and orbital period ($P = 9.3^{+1.0}_{-0.5}$ year), but has a much more eccentric orbit ($e=0.60\pm0.03$). In our joint modeling of RV and stellar activity, we found an activity-induced RV signal of $\sim$7 m s$^{-1}$, consistent with other active K dwarfs, but significantly smaller than the 31 m s$^{-1}$ reflex motion due to HAT-P-11c. We investigated the dynamical coupling between HAT-P-11b and c as a possible explanation for HAT-P-11b's misaligned orbit, finding that planet-planet Kozai interactions cannot tilt planet b's orbit due to general relativistic precession; however, nodal precession operating on million year timescales is a viable mechanism to explain HAT-P-11b's high obliquity. This leaves open the question of why HAT-P-11c may have such a tilted orbit. At a distance of 38 pc, the HAT-P-11 system offers rich opportunities for further exoplanet characterization through astrometry and direct imaging.Comment: 16 pages, 11 figures, 4 tables. Accepted to A

The anatomy of the simplest Duflo-Zuker mass formula

The simplest version of the Duflo-Zuker mass model (due entirely to the late Jean Duflo) is described by following step by step the published computer code. The model contains six macroscopic monopole terms leading asymptotically to a Liquid Drop form, three microscopic terms supposed to mock configuration mixing (multipole) corrections to the monopole shell effects, and one term in charge of detecting deformed nuclei and calculating their masses. A careful analysis of the model suggests a program of future developments that includes a complementary approach to masses based on an independently determined monopole Hamiltonian, a better description of deformations and specific suggestions for the treatment of three body forces.Comment: 30 pages, 21 figures, extensives changes to improve presentation and clarity, with an ample discussion of the anomalous term. Accepted for publication in Nuclear Physics

The role of KCNQ1 mutations and maternal beta blocker use during pregnancy in the growth of children with long QT syndrome

Synnynnäinen ionikanavasairaus pitkä QT -oireyhtymä (long QT syndrome, LQTS) on perinnöllinen hengen-vaarallisia rytmihäiriöitä aiheuttava sairaus. LQTS johtuu sydänlihassolujen ionikanavien rakenteita koodaa-vien geenien mutaatioista. Yleisimmät mutaatiot ovat KCNQ1-geenissä, ja ne aiheuttavat sairauden alamuo-don LQT1. KCNQ1 sijaitsee kromosomin 11p15.5 leimautuneella alueella, ja se koodittaa jänniteriippuvaista kaliumkanavaa, Kv7.1:a. Kaksi KCNQ1:n aktivoivaa mutaatiota aiheuttavat autosomaalisesti dominantisti periytyvän kasvuhormonin vajauksen ja äidiltä perittynä ienfibromatoosin. Tutkimuksen tarkoituksena oli analysoida LQTS -potilaiden, joilla on toiminnan hävittävä mutaatio (loss-of-function mutaatio) KCNQ1-geenissä, kasvua ja endokriinisia ominaisuuksia. Keskityimme erityisesti varhaisen kasvun ja parent-of-origin -mutaation suhteeseen. Tutkimuksessa analysoitiin LQT1-potilaiden (n=104) syntymäpituutta ja -painoa, syntymän jälkeistä kasvua ensimmäisen vuoden osalta sekä potilaiden endokriinisia ominaisuuksia. Tutkimuksessa havaittiin, että poti-laat, jotka olivat perineet KCNQ1-mutaation äidiltään, olivat syntymässä lyhyempiä kuin potilaat, jotka olivat perineet mutaation isältään. Jatkoanalyysit osoittivat, että vain potilaat, joiden äidit olivat saaneet beetasal-paajaa raskaana ollessaan, olivat lyhyempiä ja kevyempiä kuin ne potilaat, jotka olivat perineet mutaation isältään. Äidin beetasalpaajan käyttö raskauden aikana oli myös yhteydessä matalampiin napa-TSH-pitoisuuksiin sekä merkittävään saavutuskasvuun ensimmäisen elinvuoden aikana. Myöhemmin eroa ei ha-vaittu. Tutkimuksemme mukaan KCNQ1:n loss-of-function -mutaatiot eivät ole yhteydessä epänormaaliin kasvuun. Sen sijaan analyysiemme mukaan äidin raskauden aikainen beetasalpaajan käyttö näyttää rajoittavan ras-kaudenaikaista LQT1-potilaiden kasvua, mitä seuraa nopea saavutuskasvu ensimmäisen elinvuoden aikaan

Dynamic Simulation of a solar tower system with open volumetic receiver - a review on the vICERP project

The paper presents an overview on the modeling and simulation activities of the virtual institute for central receiver power plants (vICERP). Within a three years launch period models and tools for dynamic simulation of central receiver power plants have been developed by the five research institutes involved. The models are based on the Modelica modeling language. Today, models for the heliostat field, the receiver, the air cycle, the thermal storage, and the water-steam cycle are available within the consortium. As a first application, the Solar Tower Jülich technology was used as a reference. Models are validated with real operational data from the Solar Tower Jülich