Concentration Dependence of the Effective Mass of He-3 Atoms in He-3/He-4 Mixtures

Recent measurements by Yorozu et al. (S. Yorozu, H. Fukuyama, and H. Ishimoto, Phys. Rev. B 48, 9660 (1993)) as well as by Simons and Mueller (R. Simons and R. M. Mueller, Czhechoslowak Journal of Physics Suppl. 46, 201 (1976)) have determined the effective mass of He-3 atoms in a He-3/He-4 mixture with great accuracy. We here report theoretical calculations for the dependence of that effective mass on the He-3 concentration. Using correlated basis functions perturbation theory to infinite order to compute effective interactions in the appropriate channels, we obtain good agreement between theory and experiment.Comment: 4 pages, 1 figur

Musiikinopettajien käsityksiä musiikillisesta improvisaatiosta ja sille suotuisasta sosiaalisesta oppimisympäristöstä

Tiivistelmä. Tämän tutkielman tarkoitus on selvittää musiikinopettajien käsityksiä musiikillisesta improvisaatiosta ja musiikilliselle improvisaatiolle suotuisasta sosiaalisesta oppimisympäristöstä sekä sen rakentamisesta. Tutkielman tavoitteena on lisätä musiikinopettajien tietoisuutta sosiaalisen oppimisympäristön merkityksestä musiikillisen improvisaation kannalta. Teoreettisessa viitekehyksessä avataan sosiaaliseen toimintaan vaikuttavia rakenteellisia tekijöitä: sosiaalisen kehityksen, sosiaalisen oppimisympäristön ja ryhmän kehityksen sekä ryhmädynamiikan käsitteitä. Lisäksi esitellään Engeströmin toiminnan teoria, joka havainnollistaa ihmisen toiminnan kehittymisen prosessia. Tässä tutkielmassa toiminnan teoria on sijoitettu musiikillisen improvisaation sosiaaliseen oppimisympäristöön. Musiikillista improvisaatiota avataan luovuuden ja ryhmäimprovisaation näkökulmista. Luovuuden näkökulmasta musiikillinen improvisaatio rinnastuu säveltämiseen. Ryhmäimprovisaation näkökulmassa korostuu opettajan rooli improvisaation ohjaajana. Tämä tutkimus on kvalitatiivinen eli laadullinen kuvaileva tutkimus. Tutkimuksen metodologisena lähtökohtana on fenomenografinen tutkimus, jonka aineisto on kerätty teemahaastattelulla. Haastateltavina oli neljä (N=4) musiikinopettajaa, jotka käyttävät työssään musiikillista improvisaatiota ryhmäkontekstissa, kaksi heistä oli lukion ja kaksi vapaan sivistystyön musiikinopettajia. Haastateltavia yhdisti musiikillisen improvisaation käyttö musiikinopetuksen työvälineenä. Aineistoa on käsitelty sisällön analyysin metodein. Tutkimuskysymysten kannalta olennaiset vastaukset pelkistettiin ja edelleen luokiteltiin alaluokiksi, yläluokiksi ja lopuksi yhdistäviksi luokiksi. Yhdistävät luokat syntyivät prosessin aikana tehtyjen analyysien perusteella ja tulkittiin tutkielman tuloksiksi. Tutkielman tuloksina selvisi, että osallistujien käsitysten mukaan musiikillinen improvisaatio toimintana voi olla konkreettista tekemistä tai työskentelyn tapa. Ajattelutapana improvisaatio on toimintaa ohjaava myös muualla arjessa. Musiikillisen improvisaation kannalta suotuisa oppimisympäristö on turvallinen, salliva ja hyväksyvä. Opettajan pedagoginen toiminta ja didaktinen osaaminen ohjaavat opettajaa musiikillisen improvisaation kannalta suotuisan oppimisympäristön rakentamisessa. Opettajan tasapuolisuus, positiivinen palaute ja työrauhasta huolehtiminen ovat olennaisia ilmapiirin sallivuuden ja turvallisuuden näkökulmasta. Lisäksi selvisi, että oppimisympäristö rakentuu improvisoivan ryhmän jäsenten välisen vuorovaikutuksen ja kommunikaation kautta. Tällä tutkielmalla toimme näkyväksi musiikillisessa ryhmäimprovisaatiossa kommunikaation ja positiivisen vuorovaikutuksen erityisen suuren merkityksen

Single Particle and Fermi Liquid Properties of He-3/--He-4 Mixtures: A Microscopic Analysis

We calculate microscopically the properties of the dilute He-3 component in a He-3/--He-4 mixture. These depend on both, the dominant interaction between the impurity atom and the background, and the Fermi liquid contribution due to the interaction between the constituents of the He-3 component. We first calculate the dynamic structure function of a He-3 impurity atom moving in He-3. From that we obtain the excitation spectrum and the momentum dependent effective mass. The pole strength of this excitation mode is strongly reduced from the free particle value in agreement with experiments; part of the strength is distributed over high frequency excitations. Above k > 1.7$\AA$^{-1}$ the motion of the impurity is damped due to the decay into a roton and a low energy impurity mode. Next we determine the Fermi--Liquid interaction between He-4 atoms and calculate the pressure-- and concentration dependence of the effective mass, magnetic susceptibility, and the He-3--He-3 scattering phase shifts. The calculations are based on a dynamic theory that uses, as input, effective interactions provided by the Fermi hypernetted--chain theory. The relationship between both theories is discussed. Our theoretical effective masses agree well with recent measurements by Yorozu et al. (Phys. Rev. B 48, 9660 (1993)) as well as those by R. Simons and R. M. Mueller (Czekoslowak Journal of Physics Suppl. 46, 201 (1996)), but our analysis suggests a new extrapolation to the zero-concentration limit. With that effective mass we also find a good agreement with the measured Landau parameter F_0^a.Comment: 47 pages, 15 figure

Dietary fat intake and quality in long-term care residents in two cohorts assessed 10 years apart

Purpose To describe and compare detailed dietary fat intake, fat quality and associative factors between two measuring points 10 years apart of residents living in long-term care facilities, and to reflect how fat composition and fat quality corresponds to current nutrition recommendations. Methods In 2007 long-term care residents (n = 374) of 25 assisted-living facilities and nursing homes and in 2017-18 long-term care residents (n = 486) of 17 respective facilities in Helsinki metropolitan area were recruited for this study. Information on the residents' heights, demographic information and use of calcium and vitamin D supplementation were retrieved from medical records. Residents' clinical assessment included Clinical Dementia Rating (CDR), the Mini Nutritional Assessment (MNA) and questionnaire related to nutrition care. Participants' energy and fat intake were determined from 1--2-day food diaries kept by the ward nurses, and fat quality indicators calculated. Results Age, gender distribution, MNA score or body mass index did not differ between the two cohorts. Residents' cognitive status, subjective health and mobility were poorer in 2017 compared to 2007. Total fat and saturated fatty acid (SFA) intakes were higher and fat quality indicators lower in the 2017 cohort residents than in the 2007 cohort residents. Sugar intake, male gender, eating independently, eating larger amounts and not having dry mouth predicted higher SFA intake in the 2017 cohort. Conclusions The fat quality in long-term care residents in our study worsened in spite of official recommendations between the two measurement points.Peer reviewe

Quantum Rotation of HCN and DCN in Helium-4

We present calculations of rotational absorption spectra of the molecules HCN and DCN in superfluid helium-4, using a combination of the Diffusion Monte Carlo method for ground state properties and an analytic many-body method (Correlated Basis Function theory) for the excited states. Our results agree with the experimentally determined effective moment of inertia which has been obtained from the $J=0\to 1$ spectral transition. The correlated basis function analysis shows that, unlike heavy rotors such as OCS, the J=2 and higher rotational excitations of HCN and DCN have high enough energy to strongly couple to rotons, leading to large shifts of the lines and accordingly to anomalous large spectroscopic distortion constants, to the emergence of roton-maxon bands, and to secondary peaks in the absorption spectra for J=2 and J=3.Comment: accepted by Phys. Rev. B; changes: included referee suggestions, removed typos, added 10 ref

Metabolic profiling of sourdough fermented wheat and rye bread

Sourdough fermentation by lactic acid bacteria is commonly used in bread baking, affecting several attributes of the final product. We analyzed whole-grain wheat and rye breads and doughs prepared with baker's yeast or a sourdough starter including Candida milleri, Lactobacillus brevis and Lactobacillus plantarum using non-targeted metabolic profiling utilizing LC-QTOF-MS. The aim was to determine the fermentation-induced changes in metabolites potentially contributing to the health-promoting properties of whole-grain wheat and rye. Overall, we identified 118 compounds with significantly increased levels in sourdough, including branched-chain amino acids (BCAAs) and their metabolites, small peptides with high proportion of BCAAs, microbial metabolites of phenolic acids and several other potentially bioactive compounds. We also identified 69 compounds with significantly decreased levels, including phenolic acid precursors, nucleosides, and nucleobases. Intensive sourdough fermentation had a higher impact on the metabolite profile of whole-grain rye compared to milder whole-grain wheat sourdough fermentation. We hypothesize that the increased amount of BCAAs and potentially bioactive small peptides may contribute to the insulin response of rye bread, and in more general, the overall protective effect against T2DM and CVD.Peer reviewe

Scattering of He-3 Atoms from He-4 Surfaces

We develop a first principles, microscopic theory of impurity atom scattering from inhomogeneous quantum liquids such as adsorbed films, slabs, or clusters of He-4. The theory is built upon a quantitative, microscopic description of the ground state of both the host liquid as well as the impurity atom. Dynamic effects are treated by allowing all ground-state correlation functions to be time-dependent. Our description includes both the elastic and inelastic coupling of impurity motion to the excitations of the host liquid. As a specific example, we study the scattering of He-3 atoms from adsorbed He-4 films. We examine the dependence of ``quantum reflection'' on the substrate, and the consequences of impurity bound states, resonances, and background excitations for scattering properties. A thorough analysis of the theoretical approach and the physical circumstances point towards the essential role played by inelastic processes which determine almost exclusively the reflection probabilities. The coupling to impurity resonances within the film leads to a visible dependence of the reflection coefficient on the direction of the impinging particle.Comment: 36 pages, 16 figure

MYO9B polymorphisms in multiple sclerosis

"Single-nucleotide polymorphisms (SNPs) in the 30 region of myosin IXB (MYO9B) gene have recently been reported to associate with different inflammatory or autoimmune diseases. We monitored for the association of MYO9B variants to multiple sclerosis (MS) in four Northern European populations. First, 18 SNPs including 6 SNPs with previous evidence for association to immune disorders, were tested in 730 Finnish MS families, but no linkage or family-based association was observed. To ensure the power to detect variants with a modest effect size, we further analyzed 10 variants in 899 Finnish cases and 1325 controls, and in a total of 1521 cases and 1476 controls from Denmark, Norway and Sweden, but found no association. Our results thereby do not support a major function of the tested MYO9B variants in MS. European Journal of Human Genetics (2009) 17, 840-843; doi: 10.1038/ejhg.2008.251; published online 14 January 2009""Single-nucleotide polymorphisms (SNPs) in the 30 region of myosin IXB (MYO9B) gene have recently been reported to associate with different inflammatory or autoimmune diseases. We monitored for the association of MYO9B variants to multiple sclerosis (MS) in four Northern European populations. First, 18 SNPs including 6 SNPs with previous evidence for association to immune disorders, were tested in 730 Finnish MS families, but no linkage or family-based association was observed. To ensure the power to detect variants with a modest effect size, we further analyzed 10 variants in 899 Finnish cases and 1325 controls, and in a total of 1521 cases and 1476 controls from Denmark, Norway and Sweden, but found no association. Our results thereby do not support a major function of the tested MYO9B variants in MS. European Journal of Human Genetics (2009) 17, 840-843; doi: 10.1038/ejhg.2008.251; published online 14 January 2009""Single-nucleotide polymorphisms (SNPs) in the 30 region of myosin IXB (MYO9B) gene have recently been reported to associate with different inflammatory or autoimmune diseases. We monitored for the association of MYO9B variants to multiple sclerosis (MS) in four Northern European populations. First, 18 SNPs including 6 SNPs with previous evidence for association to immune disorders, were tested in 730 Finnish MS families, but no linkage or family-based association was observed. To ensure the power to detect variants with a modest effect size, we further analyzed 10 variants in 899 Finnish cases and 1325 controls, and in a total of 1521 cases and 1476 controls from Denmark, Norway and Sweden, but found no association. Our results thereby do not support a major function of the tested MYO9B variants in MS. European Journal of Human Genetics (2009) 17, 840-843; doi: 10.1038/ejhg.2008.251; published online 14 January 2009"Peer reviewe

Ulcerative colitis and irritable bowel patients exhibit distinct abnormalities of the gut microbiota

<p>Abstract</p> <p>Background</p> <p>Previous studies suggest a link between gut microbiota and the development of ulcerative colitis (UC) and irritable bowel syndrome (IBS). Our aim was to investigate any quantitative differences in faecal bacterial compositions in UC and IBS patients compared to healthy controls, and to identify individual bacterial species that contribute to these differences.</p> <p>Methods</p> <p>Faecal microbiota of 13 UC patients, 11 IBS patients and 22 healthy volunteers were analysed by PCR-Denaturing Gradient Gel Electrophoresis (DGGE) using universal and Bacteroides specific primers. The data obtained were normalized using in-house developed statistical method and interrogated by multivariate approaches. The differentiated bands were excised and identified by sequencing the V3 region of the 16S rRNA genes.</p> <p>Results</p> <p>Band profiles revealed that number of predominant faecal bacteria were significantly different between UC, IBS and control group (p < 10^-4). By assessing the mean band numbers in UC (37 ± 5) and IBS (39 ± 6), compared to the controls (45 ± 3), a significant decrease in bacterial species is suggested (p = 0.01). There were no significant differences between IBS and UC. Biodiversity of the bacterial species was significantly lower in UC (μ = 2.94, σ = 0.29) and IBS patients (μ = 2.90, σ = 0.38) than controls (μ = 3.25, σ = 0.16; p = 0.01). Moreover, similarity indices revealed greater biological variability of predominant bacteria in UC and IBS compared to the controls (median Dice coefficients 76.1% (IQR 70.9 - 83.1), 73.8% (IQR 67.0 - 77.5) and 82.9% (IQR 79.1 - 86.7) respectively). DNA sequencing of discriminating bands suggest that the presence of <it>Bacteroides vulgatus, B. ovatus, B. uniformis</it>, and <it>Parabacteroides sp</it>. in healthy volunteers distinguishes them from IBS and UC patients. DGGE profiles of Bacteroides species revealed a decrease of Bacteroides community in UC relative to IBS and controls.</p> <p>Conclusion</p> <p>Molecular profiling of faecal bacteria revealed abnormalities of intestinal microbiota in UC and IBS patients, while different patterns of Bacteroides species loss in particular, were associated with UC and IBS.</p