Electronic-structure-induced deformations of liquid metal clusters

Ab initio molecular dynamics is used to study deformations of sodium clusters at temperatures $500\cdots 1100$ K. Open-shell Na$_{14}$ cluster has two shape isomers, prolate and oblate, in the liquid state. The deformation is stabilized by opening a gap at the Fermi level. The closed-shell Na$_8$ remains magic also at the liquid state.Comment: REVTex, 11 pages, no figures, figures (2) available upon request (e-mail to hakkinen at jyfl.jyu.fi), submitted to Phys. Rev.

Stability of conductance oscillations in monatomic sodium wires

We study the stability of conductance oscillations in monatomic sodium wires with respect to structural variations. The geometry, the electronic structure and the electronic potential of sodium wires suspended between two sodium electrodes are obtained from self-consistent density functional theory calculations. The conductance is calculated within the framework of the Landauer-B\"utttiker formalism, using the mode-matching technique as formulated recently in a real-space finite-difference scheme [Phys. Rev. B \textbf{70}, 195402 (2004)]. We find a regular even-odd conductance oscillation as a function of the wire length, where wires comprising an odd number of atoms have a conductance close to the quantum unit $G_0=e^2/\pi\hbar$, and even-numbered wires have a lower conductance. The conductance of odd-numbered wires is stable with respect to geometry changes in the wire or in the contacts between the wire and the electrodes; the conductance of even-numbered wires is more sensitive. Geometry changes affect the spacing and widths of the wire resonances. In the case of odd-numbered wires the transmission is on-resonance, and hardly affected by the resonance shapes, whereas for even-numbered wires the transmission is off-resonance and sensitive to the resonance shapes. Predicting the amplitude of the conductance oscillation requires a first-principles calculation based upon a realistic structure of the wire and the leads. A simple tight-binding model is introduced to clarify these results.Comment: 16 pages, 20 figure

Broken Symmetry in Density-Functional Theory: Analysis and Cure

We present a detailed analysis of the broken-symmetry mean-field solutions using a four-electron rectangular quantum dot as a model system. Comparisons of the density-functional theory predictions with the exact ones show that the symmetry breaking results from the single-configuration wave function used in the mean-field approach. As a general cure we present a scheme that systematically incorporates several configurations into the density-functional theory and restores the symmetry. This cure is easily applicable to any density-functional approach.Comment: 4 pages, 4 figures, submitted to PR

Close-Packing of Clusters: Application to Al_100

The lowest energy configurations of close-packed clusters up to N=110 atoms with stacking faults are studied using the Monte Carlo method with Metropolis algorithm. Two types of contact interactions, a pair-potential and a many-atom interaction, are used. Enhanced stability is shown for N=12, 26, 38, 50, 59, 61, 68, 75, 79, 86, 100 and 102, of which only the sizes 38, 75, 79, 86, and 102 are pure FCC clusters, the others having stacking faults. A connection between the model potential and density functional calculations is studied in the case of Al_100. The density functional calculations are consistent with the experimental fact that there exist epitaxially grown FCC clusters starting from relatively small cluster sizes. Calculations also show that several other close-packed motifs existwith comparable total energies.Comment: 9 pages, 7 figure

Näyttöön perustuva tuki- ja liikuntaelinsairauksien kuntoutus

Kelan rahoittaman TULES- eli tuki- ja liikuntaelinsairauksien kuntoutuksen standardien kehittämistä tukevan tutkimuksen (11/2013–8/2014) yhtenä osatavoitteena oli kartoittaa keskeisin tutkimusnäyttö tuki- ja liikuntaelinsairauksien vaikuttavasta kuntoutuksesta. Tämän työpaperin tarkoitus on antaa kuntoutuksen suunnittelijoille ja käytännön työntekijöille tietoa tämänhetkisen TULES-kuntoutuksen tutkimuksen tuloksista. Järjestelmällinen kirjallisuuskatsaus tuo esille vaikuttavaksi osoitettuja kuntoutusmuotoja. Tähän kirjallisuuskatsaukseen on lisäksi kerätty tietoa eri maiden kuntoutussuosituksista alaselän, niskan, olkapään sekä polven ja lonkan TULE-sairauksien osalta sekä kuntouttavan liikuntaharjoittelun perusteista. Järjestelmällinen tiedonhaku suoritettiin viiden vuoden ajalta; vuoden 2009 alusta vuoden 2013 loppuun saakka. Järjestelmällisen katsauksen päätulokset osoittivat aktiiviseen terapeuttiseen harjoitteluun perustuvien ohjelmien olevan vaikuttavia kaikkien katsauksessa mukana olleiden TULE-sairauksien kuntoutuksessa. Lisäksi todettiin manuaalisen terapian olevan vaikuttavaa alaselän ja niskan kuntoutuksessa. Kohtalaista tutkimusnäyttöä löytyi tiettyjen fysikaalisten hoitojen, mm. akupunktion, laserterapian ja pulsoivan magneettiterapian vaikuttavuudesta jokaisessa tutkitussa TULE-sairaudessa. Ohjauksellisista interventioista ainoastaan behavioraalisen terapian vaikuttavuus on osoitettu kohtalaiseksi alaselän kuntoutuksessa. Eri maiden ja yhdistysten suositukset painottavat tutkimusnäytön mukaisesti aktiivista harjoittelua niin selkä-, niska- kuin nivelkuntoutuksessa

Temperature dependence of surface reconstructions of Au on Pd(110)

Surface reconstructions of Au film on Pd(110) substrate are studied using a local Einstein approximation to quasiharmonic theory with the Sutton-Chen interatomic potential. Temperature dependent surface free energies for different coverages and surface structures are calculated. Experimentally observed transformations from $(1\times1)$ to $(1 \times 2)$ and $(1 \times 3)$ structures can be explained in the framework of this model. Also conditions for Stranski-Krastanov growth mode are found to comply with experiments. The domain of validity of the model neglecting mixing entropy is analyzed.Comment: 7 pages, REVTeX two-column format, 3 postscript figures available on request from [email protected] To appear in Phys. Rev. Letter

Common Origin for Surface Reconstruction and the Formation of Chains of Metal Atoms

During the fracture of nanocontacts gold spontaneously forms freely suspended chains of atoms, which is not observed for the iso-electronic noble metals Ag and Cu. Au also differs from Ag and Cu in forming reconstructions at its low-index surfaces. Using mechanically controllable break junctions we show that all the 5d metals that show similar reconstructions (Ir, Pt and Au) also form chains of atoms, while both properties are absent in the 4d neighbor elements (Rh, Pd, Ag), indicating a common origin for these two phenomena. A competition between s and d bonding is proposed as an explanation

Substantial fat mass loss reduces low-grade inflammation and induces positive alteration in cardiometabolic factors in normal-weight individuals

( )The accumulation of fat, especially in visceral sites, is a significant risk factor for several chronic diseases with altered cardiometabolic homeostasis. We studied how intensive long-term weight loss and subsequent weight regain affect physiological changes, by longitudinally interrogating the lipid metabolism and white blood cell transcriptomic markers in healthy, normal-weight individuals. The current study examined 42 healthy, young (age: 27.5 +/- 4.0 years), normal-weight (body mass index, BMI: 23.4 +/- 1.7 kg/m(2)) female athletes, of which 25 belong to the weight loss and regain group (diet group), and 17 to the control group. Participants were evaluated, and fasting blood samples were drawn at three time points: at baseline (PRE); at the end of the weight loss period (MID: 21.1 +/- 3.1 weeks after PRE); and at the end of the weight regain period (POST: 18.4 +/- 2.9 weeks after MID). Following the weight loss period, the diet group experienced a similar to 73% reduction (similar to 0.69 kg) in visceral fat mass (false discovery rate, FDR <2.0 x 10(-16)), accompanied by anti-atherogenic effects on transcriptomic markers, decreased low-grade inflammation (e.g., as alpha(1)-acid glycoprotein (FDR = 3.08 x 10(-13)) and hs-CRP (FDR = 2.44 x 10(-3))), and an increase in functionally important anti-atherogenic high-density lipoprotein -associated metabolites (FDR <0.05). This occurred even though these values were already at favorable levels in these participants, who follow a fitness-lifestyle compared to age- and BMI-matched females from the general population (n = 58). Following the weight regain period, most of the observed beneficial changes in visceral fat mass, and meta bolomic and transcriptomic profiles dissipated. Overall, the beneficial anti-atherogenic effects of weight loss can be observed even in previously healthy, normal-weight individuals.Peer reviewe

Rapid circulation of warm subtropical waters in a major glacial fjord in East Greenland

Author Posting. © The Authors, 2009. This is the author's version of the work. It is posted here by permission of Nature Publishing Group for personal use, not for redistribution. The definitive version was published in Nature Geoscience 3 (2010): 182-186, doi:10.1038/ngeo764.The recent rapid increase in mass loss from the Greenland Ice Sheet is primarily attributed to an acceleration of outlet glaciers. One possible cause is increased melting at the ice/ocean interface driven by the synchronous warming of subtropical waters offshore of Greenland. This hypothesis is largely untested, however, because of the lack of observations from Greenland’s glacial fjords and our limited understanding of their dynamics. Here, we present new ship-based and moored oceanographic data, collected in Sermilik Fjord, a large glacial fjord in East Greenland, showing that subtropical waters are present throughout the fjord and are continuously replenished via a wind-driven exchange with the shelf, where they occur year-round. The temperature and rapid renewal of these waters suggest that, at present, they drive enhanced submarine melting at the terminus. Key controls on the melting rate are the volume and properties of subtropical waters on the shelf and the patterns of the along-shore winds, suggesting the glaciers’ acceleration was triggered by a combination of atmospheric and oceanic changes. These measurements provide evidence of rapid advective pathway for the transmission of oceanic variability to the ice-sheet margins and highlight an important process that is missing from prognostic ice-sheet models.F.S. acknowledges support from WHOI’s Ocean and Climate Change Institute’s Arctic Research Initiative and from NSF OCE 0751896, and G.S.H and L.A.S from NASA’s Cryospheric Sciences Program. Funding for the hooded seal deployments was obtained from the International Governance and Atlantic Seal Research Program, Fisheries and Oceans, Canada, to G. B. S. and to the Greenland Institute of Natural Resources to A. R. A

Anduril 2: Upgraded large-scale data integration framework

aSummary: Anduril is an analysis and integration framework that facilitates the design, use, parallelization and reproducibility of bioinformatics workflows. Anduril has been upgraded to use Scala for pipeline construction, which simplifies software maintenance, and facilitates design of complex pipelines. Additionally, Anduril's bioinformatics repository has been expanded with multiple components, and tutorial pipelines, for next-generation sequencing data analysis.Peer reviewe