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Within finite-range density-functional theory, we have addressed the photo-ejection of electrons hosted in He bubbles as a function of pressure at zero temperature. It is shown that, besides the 1 s→1 p and 1 s→2 p transitions that show up in the whole pressure range up to solidification, there is another transition to a loosely bound 3 p state that disappears at a pressure P above 1.7 bar. Realistic predictions for the electron photo-ejection cross section are made using a model that has been proven to reproduce the experimental infrared absorption transitions as a function of pressure. [ABSTRACT FROM AUTHOR]

Within density functional theory, we have addressed the solvation onset of Ca atoms in small, mixed helium drops. As a case of study, we have considered a Ca@4He50 droplet to which we have first added one single 3He atom. Next, the structure of spin-saturated Ca@3He N3+4He50 droplets with N3=18, 32, 50 and 68 is determined and used to infer the number of 3He atoms needed to solvate the Ca atom for that particular system. [ABSTRACT FROM AUTHOR]

The expression of IFNβ in beta cells results in accelerated type 1 diabetes. The REG family of beta cell proliferation factors have been described as autoantigens in autoimmune diabetes. The aim of this study was to determine the effect of IFNβ on Reg expression, and the implications of this in terms of autoimmunity. Reg gene expression was determined in islets from non-obese diabetic (NOD) RIP-HuIFNβ mice by cDNA microarray, quantitative real-time PCR and immunohistochemistry. The effect of IFNβ on Reg1 and Reg2 expression was assessed in the NOD insulinoma cell line NIT-1. IL-6, known to induce Reg expression, was measured in the insulitis microenvironment. Morphological studies were carried out to determine islet enlargement in this model. Reg2 was upregulated in islets from the NOD RIP-HuIFNβ mice at the onset of the autoimmune attack. IFNβ upregulates Reg1 and Reg2 genes in NIT-1 cells. The expression of Il6 was increased in islets from transgenic mice and in NIT-1 cells exposed to HuIFNβ. Moreover, islets from transgenic mice were enlarged compared with those from wild-type mice. Reg overexpression correlates well with the acceleration of diabetes in this model. The upregulation of Reg suggests that islets try to improve hyperglycaemia by regenerating the cells lost in the autoimmune attack. Reg expression is regulated by several factors such as inflammation. Therefore, the overexpression of an IFNβ-induced autoantigen (REG) in the islets during inflammation might contribute to the premature onset of diabetes. [ABSTRACT FROM AUTHOR]

We investigate the behavior of mixed 3He–4He droplets on alkali surfaces at zero temperature, within the frame of Finite Range Density Functional theory. The properties of one single 3He atom on $$^4 He_{N_4 }$$ droplets on different alkali surfaces are addressed, and the energetics and structure of $$^4 He_{N_4 } + ^3 He_{N_3 }$$ systems on Cs surfaces, for nanoscopic 4He drops, are analyzed through the solutions of the mean field equations for varying number N3 of 3He atoms. We discuss the size effects on the single particle spectrum of 3He atoms and on the shapes of both helium distributions. [ABSTRACT FROM AUTHOR]

We examine the structure and energetics of 4He drops with added ³He atoms, deposited on flat alkali surfaces at zero temperature, and find that single ³He particles populate one dimensional bound states localized around the contact line. We analyze the possibility of a new type of Luttinger liquid behavior in mixtures of helium isotopes on Cs substrates, and examine possible measurable manifestations of the presence of these rings, such as the spectrum of undamped spin density fluctuations. [ABSTRACT FROM AUTHOR]

We use density functional theory to investigate the structure of mixed 3 He N 3− 4 He N 4 droplets with an embedded Xe atom that pins a quantized vortex line. While 3He atoms are distributed along the vortex line and on the surface of the 4He drop, the impurity is mostly coated by 4He atoms. Results for N 4= 500 and a number of 3He atoms up to N 3= 100 are presented, and the binding energy of the dopant to the vortex line is determined. [ABSTRACT FROM AUTHOR]

We investigate the properties of liquid 4HeN clusters hosting a quantized vortex pinned to a dopant atom (Ne or Xe) or molecule (SF 6 or HCN). A density functional theory is used to calculate the stationary configurations of pure and doped clusters, with and without vortex, up to N= 1000. A liquid drop formula is then proposed that accurately describes the total energy of the complex and allows one to extrapolate the results to larger N values. We find that forming a dopant+vortex+ 4HeN complex is energetically favored below a critical size N cr, which strongly depends on the type of dopant. [ABSTRACT FROM AUTHOR]

We present an overview of the gene content and organization of the mitochondrial genome of Dictyostelium discoideum. The mitochondria genome consists of 55,564 bp with an A + T content of 72.6%. The identified genes include those for two ribosomal RNAs ( rnl and rns), 18 tRNAs, ten subunits of the NADH dehydrogenase complex ( nad1, 2, 3, 4, 4L, 5, 6, 7, 9 and 11), apocytochrome b ( cytb), three subunits of the cytochrome oxidase ( cox1/2 and 3), four subunits of the ATP synthase complex ( atp1, 6, 8 and 9), 15 ribosomal proteins, and five other ORFs, excluding intronic ORFs. Notable features of D. discoideum mtDNA include the following. (1) All genes are encoded on the same strand of the DNA and a universal genetic code is used. (2) The cox1 gene has no termination codon and is fused to the downstream cox2 gene. The 13 genes for ribosomal proteins and four ORF genes form a cluster 15.4 kb long with several gene overlaps. (3) The number of tRNAs encoded in the genome is not sufficient to support the synthesis of mitochondrial protein. (4) In total, five group I introns reside in rnl and cox1/2, and three of those in cox1/2 contain four free-standing ORFs. We compare the genome to other sequenced mitochondrial genomes, particularly that of Acanthamoeba castellanii. [ABSTRACT FROM AUTHOR]

The far infrared longitudinal spin and density responses of two-dimensional quantum dots are discussed within local spin-density functional theory. The influence of a partial spin polarization, induced by a perpendicular static magnetic field, is taken into account in the coupling of spin and density channels. As an illustrative application, the case of a dot made of 5 electrons in parabolic confinement is discussed. [ABSTRACT FROM AUTHOR]

We present a study of phase separation from supersaturated3 He-4 He liquid mixtures at low temperatures addressing both the degree of critical supersaturation Δxcr and the thermal-to-quantum crossover temperature T* for the nucleation process. Two different nucleation seeds are investigated, namely3 He droplets and4 He vortex lines with cores filled with3 He. We have found that the experimental T* is reproduced when we consider that nucleation proceeds from3 He droplets, whereas Δxcr is reproduced when we consider4 He vortex lines filled with3 He. However, neither nucleation configuration is able to simultaneously reproduce the current experimental information on Δxcr and T*. [ABSTRACT FROM AUTHOR]

We have investigated the collision ofHe drops in the normal phase by means of the Vlasov equation. The structure and dynamics of the drops have been described by a density functional that takes properly into account relevant properties of the homogeneous liquid. Results forHe-He collisions at different energies and impact parameters are presented. [ABSTRACT FROM AUTHOR]

We have computed the density of states and the evaporation rate ofHe clusters, paying special attention to finite size effects which modify theHe level density parameter and chemical potential from their bulk values. Ready-to-use liquid-drop expansions of these quantities are given. [ABSTRACT FROM AUTHOR]

An analysis of helium cluster properties at finite temperature using a phenomenological free energy density has been carried out. We have studied in detail the energetics and the density profile characteristics of hot drops of both helium isotopes containing 70, 112, 168, 240 and 330 atoms. A finite temperature mass formula including volume, surface and curvature terms has been derived. [ABSTRACT FROM AUTHOR]

Using an effectiveHe-He interaction, we have investigated the fission and fusion ofHe drops from a static point of view. Our calculations show that a fission barrier develops for these neutral systems, and that their saddle configurations are rather elongate. The transition from oblate to prolate shapes as a function of the angular momentum L, as well as critical values for fission and fusion are discussed for some selected cases. We show that a kind of proximity potential can be extracted from the drop-drop interaction potentials. [ABSTRACT FROM AUTHOR]

In this study, we analyzed a mitochondrial small (ms) RNA in Dictyostelium discoideum, which is 129 nucleotides long and has a GC content of only 22.5%. In the mitochondrial DNA, a single-copy gene ( msr) for the ms RNA was located downstream of the gene for large-subunit rRNA. The location of msr was similar to that of the 5S rRNA gene in prokaryotes and chloroplasts, but clearly different from that in mitochondria of plants, liverwort and the chlorophycean alga Prototheca wikerhamii, in which small-subunit rRNA and 5S rRNA genes are closely linked. The primary sequence of ms RNA showed low homology with mitochondrial 5S rRNA from plants, liverwort and the chlorophycean alga, but the proposed secondary structure of ms RNA was similar to that of cytoplasmic 5S rRNA. In addition, ms RNA showed a highly conserved GAAC sequence in the same loop as in common 5S rRNA. However, ms RNA was detected mainly in the mitochondrial 25 000 × g supernatant fraction which was devoid of ribosomes. It is possible that ms RNA is an evolutionary derivative of mitochondrial 5S rRNA. [ABSTRACT FROM AUTHOR]

We sequenced a region of about 14.5 kb downstream from the ribosomal protein L11 gene ( rpl11) in the mitochondrial DNA (54±2 kb) of the cellular slime mold Dictyostelium discoideum. Sequence analysis revealed that eleven ribosomal protein genes and six open reading frames (ORFs) formed a cluster arranged in the order: rpl11– orf189– rps12– rps7– rpl2– rps19– orf425– orf1740– rpl16– rpl14– orf188– rps14– rps8– rpl6– rps13– orf127– orf796. This order was very similar to that of homologous genes in Acanthamoeba castellanii mitochondrial DNA. The N-terminal region of ORF425 and the C-terminal region of ORF1740 had partial similarities to the S3 ribosomal protein of other organisms. The termination codons of rpl16 and orf188 were UGA, which has not hitherto been found in genes encoded in D. discoideum mitochondrial DNA. [ABSTRACT FROM AUTHOR]

The spinodal decomposition of heavy-ion-induced nuclear systems is analyzed with the help of Landau-Vlasov simulations. Estimates of the multifragmentation cross-sections are given, in the framework of a schematic model. [ABSTRACT FROM AUTHOR]

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The effect of ring vortices on the destabilization of supersaturated liquid helium mixtures at very low temperatures is investigated as a function of pressure. We have found that large ring vortices trigger the segregation of3 He at smaller values of the concentration than small ring vortices. Our calculations indicate that the existence of ring vortices in the mixture is a possible mechanism to understand the rather small degree of critical super-saturation found in the experiments. [ABSTRACT FROM AUTHOR]

We describe a simple dynamical model for the production of prompt nucleons at the very beginning of a heavy ion collision. Approximations often used in previous calculations (neglect of Pauli blocking, of window velocity and of its extension) have been checked. We apply the model to the calculation of prompt emitted neutrons in incomplete fusion reactions observed on theNe+Ho system at 220, 402 and 700 MeV. Results of the model are extensively discussed. [ABSTRACT FROM AUTHOR]

We have investigated the static fission and fusion ofHe drops using a density functional. Our calculations show that a fission barrier develops for these neutral systems, and that their saddle configurations are rather elongate. We show that a kind of proximity potential can be extracted from the drop-drop interaction potentials. [ABSTRACT FROM AUTHOR]

The dipole surface plasmon for K clusters is analyzed using the RPA sum-rule technique within a semiclassical Density Functional Theory and the spherical jellium model. The theoretical frequencies are blue shifted as compared to the experimental ones. The discrepancies between theory and experiment are reduced when considering non-local energy contributions in the density functional and phenomenologically including atomic lattice effects by means of an electron effective mass and a static dielectric constant. [ABSTRACT FROM AUTHOR]